This paper systematically reviews the research progress and applications of light-curing 3D printing technology in various fields. Firstly, the principles and main methods of light-curing technology are introduced, including stereolithography (SLA), mask projection stereolithography (MPSL), two-photon polymerization (TPP), and digital light processing (DLP), with analysis of their technical characteristics. Secondly, the composition, modification methods, and research status of photosensitive resins for performance enhancement are discussed in detail. The focus is on the applications of light-curing technology in medical fields (such as dental restoration, tissue engineering scaffolds, tumor models, and flexible monitoring sensors), as well as in electronic information and mechanical manufacturing. Finally, the future development directions of light-curing technology are prospected, emphasizing the key role of material innovation and process optimization in promoting the integration of medicine and engineering and intelligent manufacturing.

This article provides a brief overview of the overall development and the breakdown of PM (powder metallurgy) products usage of China's powder metallurgy products industry. It covers the growth and market structure of the traditional powder metallurgy parts sector in China, as well as recent developments in automotive components, home appliance parts, and oil-impregnated bearings. The main technological advancements in China's powder metallurgy parts are briefly outlined. It also touches upon the impacts of the rapid development of new energy vehicles in China on the traditional ICE vehicle market and its subsequent effects on the traditional powder metallurgy parts industry. Additionally, it offers a brief analysis of the opportunities and challenges that the China's powder metallurgy products industry is likely to encounter in the future amid the rapid growth of emerging industries.

【Objective】The purpose of this review is to systematically examine the current state and challenges of solid-state hydrogen storage, with a focus on the interconnection between material dynamic responses and system integration optimization. It aims to bridge the gap between fundamental material properties and practical engineering applications, thereby providing a comprehensive framework to guide the development of efficient and commercially viable next-generation systems.
【Method】This study was conducted through a systematic literature review, synthesizing recent research advances across two interconnected domains. First, the thermodynamic and kinetic properties, cyclic stability, and dynamic responses of major solid-state hydrogen storage materials, such as metal hydrides and complex hydrides, were analyzed. Second, system-level integration and optimization approaches for hydrogen storage devices were investigated. This encompassed the analysis of heat exchanger design, temperature and pressure control strategies, various structural configurations, as well as safety protocols and techno-economic assessments. The methodology integrated theoretical models, such as the Van't Hoff equation and the shrinking core model, with numerical simulations including multi-physics coupling and computational fluid dynamics (CFD) for safety analysis. Empirical data from representative case studies, including the Toyota Mirai and the NEDO project, were incorporated to establish a holistic “material-device-system” analysis framework.
【Result】The analysis indicates that the performance of solid-state hydrogen storage systems is dictated by a complex interplay between material properties and engineering design. Key findings include: (1) Material performance often involves inherent trade-offs, for example, between high hydrogen capacity and rapid reaction kinetics. Modification strategies, such as nanostructuring and catalytic doping, can enhance performance but may concurrently compromise long-term stability or increase cost. (2) System integration presents significant challenges in thermal management. The strongly exothermic/endothermic nature of hydrogenation/dehydrogenation necessitates highly efficient heat transfer designs, which typically utilize high-conductivity matrices, phase-change materials, and advanced heat exchangers to ensure reaction uniformity and system stability. (3) Safety and reliability remain critical, requiring multi-level protection systems, redundant design principles, and rigorous risk assessments to mitigate hazards such as hydrogen leakage. (4) Economic viability remains a major concern, with costs heavily influenced by premium materials, complex manufacturing processes, and sophisticated control systems. However, modular design and scaled-up production present viable pathways for cost reduction.
【Conclusion】Solid-state hydrogen storage technology represents a promising pathway for safe, high-density hydrogen storage, yet its advancement necessitates coordinated innovation across materials science and systems engineering. Future efforts should focus on developing low-cost, high-capacity materials with favorable thermodynamics and kinetics, concurrently advancing integrated system designs for efficient thermal management, robust safety, and improved economic competitiveness. A synergistic approach leveraging advanced characterization, multi-scale modeling, and intelligent control is crucial for overcoming existing bottlenecks and accelerating the commercialization of this technology for applications ranging from transportation to stationary energy storage.

【Objective】This study investigates the mechanism of central lithium plating in lithium iron phosphate (LiFePO₄) batteries during high-rate discharge (3C), establishes a temperature‑infiltration coupling model to explain the phenomenon, and proposes both fundamental and tactical improvement strategies.
【Method】Cycling tests, inductively coupled plasma (ICP), and in‑situ ultrasonic testing were employed. Experiments were conducted using 61 Ah pouch‑type LiFePO₄ cells subjected to a demanding cycle protocol: 0.5C charge, 10 min rest, and 3C discharge, repeated for up to 200 cycles—exceeding the cells’ rated discharge capability. Comparative modifications included increasing the cathode conductive carbon black content from 1% to 3.5%, reducing electrode compaction density, and adjusting charge‑discharge strategies (e.g., stepped discharge, extended rest periods, and periodic low‑current conditioning).
【Result】Under the high‑rate discharge protocol, cells exhibited rapid capacity degradation after 150 cycles, with a capacity retention of 88.3% at 200 cycles and pronounced central lithium plating. Ultrasonic and temperature measurements revealed intensified electrolyte breathing effects and temperature gradients during 3C discharge. The proposed temperature-infiltration coupling model indicates that during the 3C discharge process of a fully charged cell, both temperature effects and breathing effects occur simultaneously. Their combined influence results in, during the subsequent charging process, the lateral diffusion of Li⁺ between the anode layers toward the center, along with the continuous intercalation of lithium from the cathode into the anode. This eventually leads to the formation of a lithium-rich region on the surface of the central anode area by the end of charging, where lithium preferentially plates. As the cycle process accumulates, the lithium plating in the central anode region evolves into black spots. Among the improvement strategies, increasing the cathode conductive carbon black to 3.5% proved most effective: after 200 cycles under 3C conditions, capacity retention improved from 95.9% to 98.5%, and central lithium plating was substantially suppressed. Tactical measures ranked as follows in effectiveness: a 3 h rest after each discharge > stepped discharge > low‑current conditioning every 50 cycles > conventional protocol.
【Conclusion】(1) Both breathing effects and temperature gradients exist during charge‑discharge in LFP pouch cells and are significantly exacerbated under high‑rate discharge conditions. (2) The temperature‑infiltration coupling model explains central lithium plating: during 3C discharge, the central region experiences higher temperature and faster lithium‑ion transport, leading to earlier depletion of the central anode, combined with electrolyte squeezing during high‑rate discharge, the central area becomes deficient in electrolyte. In the subsequent rest period, solid‑phase diffusion occurs but is incomplete, and electrolyte rewetting is insufficient given the short rest time. During the following 0.5C charge, the central N/P ratio decreases, and inhomogeneous lithium intercalation creates a potential gradient, driving lateral lithium diffusion toward the center and resulting in preferential lithium deposition. This effect accumulates over cycles, evolving into black‑spot lithium plating in the central anode region. (3) Fundamental improvements—such as increasing positive electrode conductive carbon black to 3.5% and lowering electrode compaction density—effectively mitigate central lithium plating and significantly enhance high‑rate cycling performance. Tactical measures, particularly extended rest after discharge, also provide meaningful suppression. These findings support the development of LiFePO₄ cells with improved high‑rate cycle life and enhanced competitiveness in power applications.

in this paper, ultrafine silver powder was prepared by liquid-phase chemical method. The effects of feeding rate, reaction temperature, concentration of silver nitrate, refining dose and alkali temperature on the properties of ultrafine silver powder were studied, the morphology was observed by scanning electron microscopy (SEM). The results show that when the AgNO₃ concentration, AgNO₃ feeding rate, reaction temperature, refining dose and alkali temperature are 0.15 mol/L、200 L/S、55 ℃、35 g、30 ℃, the agglomerations of ultrafine silver powder are less, the particle sizes are uniform and the distribution is concentrated, show excellent performance.

【Objective】O3-type NaNi_1/3Fe_1/3Mn_1/3O₂ (NFM111) layered oxide is a promising cathode for sodium-ion batteries due to its high capacity, low cost, and simple synthesis. However, its practical application is hindered by complex phase transitions, transition metal migration, interfacial side reactions, and poor air stability. This review summarizes recent modification strategies and provides insights into structure-performance relationships to guide future research.
【Method】This paper systematically reviews advances in NFM111 modification in recent years, categorizing them into three approaches: elemental doping, surface coating, and morphology/microstructure regulation. For each strategy, the underlying mechanisms, summarize key experimental findings, and evaluate advantages and limitations were analyzed. The emerging trends including multi-strategy synergistic modification, theoretical calculations and artificial intelligence were also discussed.
【Result】Elemental doping at transition metal, sodium, or oxygen sites effectively stabilizes the bulk structure through "pinning effects”, suppresses harmful phase transitions, and widens Na⁺ diffusion channels. Appropriate dopants significantly enhance cycling stability and mitigate Jahn-Teller distortion. Multi-element co-doping strategies, including high-entropy compositions, achieve synergistic improvements in structural stability during prolonged cycling. Surface coating constructs protective interfacial layers that isolate electrolyte erosion and improve air stability, various oxide and phosphate coatings have demonstrated particular promise. Notably, combined doping-coating approaches simultaneously address bulk and interfacial instability, leading to enhanced structural integrity and prolonged cycle life. Morphology and microstructure regulation through single-crystallization reduces intergranular cracking and enhances mechanical stability, while concentration gradient designs with transition metal compositional variations enable improved structural robustness and enhanced air stability.
【Conclusion】Future research on O3-type NaNi_1/3Fe_1/3Mn_1/3O₂ should prioritize multi-strategy synergistic modifications that enhance both bulk and interfacial stability. Understanding degradation mechanisms through advanced in-situ characterization, along with density functional theory and artificial intelligence-assisted screening, will accelerate materials discovery. Developing scalable synthesis processes for gradient structures and uniform coatings is also essential for commercial viability. With continued progress, NFM111-based cathodes hold great promise for low-cost, high-performance sodium-ion batteries in grid-scale energy storage.

Sinter hardening typically refers to the process during the later stages of continuous sintering where the material partially or fully transforms into martensite at relatively low cooling rates (1-3 °C/s). Compared to traditional heat treatment processes, material strengthening can be achieved simply by controlling the cooling rate in the later stages of sintering, offering a cost advantage in the process. This method is also known as the one step process. This article analyzes the research work of domestic and foreign scholars on sintered hardening powder in recent years, and elaborates on the research progress of sintered hardening powder from the aspects of composition design, alloy elements, and the influence of sintering processes on hardening properties. It also summarizes some of the technical issues currently encountered with sinter hardening powders, expanding the selection of alloy elements and improving the sintering hardening process in a targeted manner will be the development direction of sintering hardening powder in the future. Expanding the selection of alloy elements and improving the sintering hardening process in a targeted manner will be the development direction of sintering hardening powder in the future.

Temperature range of solid-liquid phase line of self-fluxing alloy powder is an important considering factor for the setting of welding process parameters, and it is also an important parameter affecting the properties of such materials and thermal spraying、 laser cladding and 3D printing quality. It is particularly important to determine the precise solid-liquidus temperature range of self-fluxing alloy powder. In this paper, the melting and solidification curves of self-fluxing alloy powder were measured by DSC according to the standard YS/T533-2006, and the correct method of determination of solid-liquidus and the optimal measurement parameter were discussed. The experimental results show that, the obtained onset solidification temperature is lower than the onset melting temperature during the heating process because of the existence of supercooling during solidification, which is inconsistent with the characteristic that the liquidus is higher than the solid phase line in the binary phase diagram. The solid-liquidus of the self-fluxing alloy should be measured according to the melting curve, and the melting starting and ending temperatures correspond to the solid-phase and liquidus temperatures, respectively. In addition, the experimental results of different heating rates and sample mass show that the test results have good repeatability when the heating rate is 4-10 ℃/min and the sample mass is 5-50 mg, 10 ℃ and 15 mg is recommended.

A composite gradient porous membrane material was successfully prepared using a combination of cold isostatic pressing, centrifugal deposition molding technology, and vacuum sintering, with 316L porous stainless steel as the matrix and ZrO₂ as the membrane layer. The phase composition, microporous structure morphology, and pore properties of porous materials were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and a porous material integrity tester. The influence of sintering temperature on the pore structure morphology, air permeability coefficient, and pore size distribution of 316L-ZrO₂ composite gradient porous membrane material was studied, and finally its filtration application in the treatment of oily and saline wastewater was studied using dead-end filtration technique. The results show that by introducing a correction factor K into the formula for calculating the thickness of the gradient membrane layer, accurate control of the membrane thickness can be achieved. In this experiment the K value ranged from 0.21 to 0.25. The permeability of the membrane material decreases gradually as the sintering temperature rises, and the reduction in the permeability coefficient is more pronounced at 700-800°C. Meanwhile, the average pore size of the membrane layer becomes smaller, decreasing from 0.28 µm to 0.18 µm. The 316L-ZrO₂ composite gradient porous membrane can effectively remove suspended solids from oily and saline wastewater, but has poor removal effects on COD, ammonia nitrogen, and soluble salts.

The labyrinth seal is an important pneumatic sealing structure in aircraft engines. In order to prevent wear and damage between the labyrinth and the metal honeycomb during operation, a nickel aluminum alumina wear-resistant protective coating was prepared on the surface of the labyrinth by plasma spraying. The coating is complete and well bonded. The service performance of the coating under simulated working conditions was tested using a high-temperature and high-speed abrasion tester. The results show that after scraping with labyrinth and honeycomb, significant plastic deformation occurres in the honeycomb. The labyrinth mainly undergo cutting and wear, with obvious application, adhesion, and accumulation of honeycomb material on the surface. Increasing the line speed and feed depth can aggravate the damage and deformation of the honeycomb and the adhesion to the surface of the grate teeth. The tip of the labyrinth do not show significant wear and deformation, indicating that the coating do not undergo large peeling during the grinding and scraping process, but is cyclically worn by honeycomb layers, and the coating provides good protection for the labyrinth. Under the testing conditions of a linear velocity of 300 m/s and a feed depth of 300 μm, the maximum values of tangential and radial forces during impact grinding are 999.51 N and 582.52 N, respectively, achieving a small gap structure for the rotor and effectively ensuring the sealing effect of the gas path.

The influence of physical properties of tantalum powder on the shapeability of tantalum anode blocks was analyzed. The results show that the pressing and shaping of tantalum electrolytic anode blocks is closely related to the physical properties of tantalum powder, such as fluidity, particle size distribution, and the size of the aggregated particles after subsequent agglomeration treatment. When the Fisher particle size of the sample increases from 6 μm to 16.4 μm and the particle size distribution span decreases from 1.76 to 0.96, the flowability improves significantly. Concurrently, the compactibility of the tantalum powder is markedly enhanced, with compressive strength increasing from 4.6 MPa to 14.6 MPa, and the bonding with tantalum wire leads become more robust.

Focusing on the sensitivity of WNiFe alloys to tensile rate, 93WNiFe alloy was selected as the research object. Through uniaxial static tensile tests under different tensile rates, combined with fracture morphology analysis, the effects of tensile rate on its tensile properties (tensile strength, elongation after fracture) and fracture mechanism were investigated, and the sensitivity coefficient was introduced to quantify the sensitivity. The results show that 93WNiFe alloy has high sensitivity to tensile rate, presenting the characteristic of "high sensitivity in low rate range and low sensitivity in high rate range". As the tensile rate increases from 0.18 mm/min to 19.29 mm/min, the tensile strength increases from 889 MPa to 940 MPa (with an increase of 5.7%), and the elongation after fracture decreases from 32.5% to 22.0% (with a decrease of 32.3%). The sensitivity coefficient indicates that the sensitivity is the highest in the 0.18→0.45 mm/min range (tensile strength S≈48.15 MPa·min/mm, elongation after fracture S≈-11.11%·min/mm), while it decreases significantly in the 12.06→19.29 mm/min range (tensile strength S≈0.28 MPa·min/mm, elongation after fracture S=0). On the micro mechanism, the increase of tensile rate leads to the transformation of fracture mode from "dominated by tungsten-tungsten interface separation" to "dominated by transgranular fracture of tungsten particles", which is the main reason for the improvement of tensile strength. Meanwhile, the proportion of fracture phase decreases from 3.68% to 0.66%, resulting in the reduction of elongation after fracture. The research results can provide a theoretical reference for the application of 93WNiFe alloy under different service rate conditions.

High voltage rare earth permanent ferrite Ca_0.85-yLa_ySr_0.15Fe_2n-0.3Co_0.3O_19-δ was prepared by ceramic technology. The magnetic characteristics, voltage resistance and microstructure of the products were detected and analyzed by pressure tester, permanent ferrite measuring instrument and scanning electron microscope. The results show that under specific technological conditions, the magnetic properties and voltage resistance of the material are significantly improved with the replacement of n and La in the main formula and the addition of appropriate SiO₂. When n=5.3, y=0.36, and the pre-sintering temperature is at 1 260 ℃, the pre-sintering material come into being. Then during fine grinding, 0.15%SiO₂ is added. Combined with the slow heating (1 ℃/min) and fast cooling sintering (10 ℃/min) process of the formed compact between 1 100-1 180 ℃, rare earth permanent magnet ferrite with (BH)_max to 36.37 kJ/m³ excellent magnetic properties and high pressure resistance (AC1 500 V, 2.4 mA leakage current) can be obtained.

The electrode induction melting gas atomization (EIGA) technology was successfully used to overcome the technical difficulties in preparing spherical rare earth gadolinium powder. The effect of different atomization pressures on the particle size of the powder was studied. The optimal rare earth gadolinium atomization process for this experiment is: atomization power of 43 kW, rod descent speed of 20 mm/min, rotation speed of 5 r/min, and atomization pressure of 5.0 MPa. The apparent morphology, particle size, and flowability of the spherical powder were measured using scanning electron microscopy, particle size analyzer, and Hall flowmeter. After 60 mesh sieving, the performance of gadolinium powder is determined as follows: powder particle size D₁₀=22.29 μm, D₅₀=59.71 μm、D₉₀=121.3 μm, liquidity of 28.33 s/50g, loose density of 4.36 g/cm³, compacted density of 5.15 g/cm³, good sphericity, and no introduction of non-metallic inclusions.

In order to further improve the accuracy of compositional control of Fe-Mn-Si system memory alloys to ensure their properties, the interaction of three main process parameters, namely, ball milling time, sintering temperature, and sintering time, on the densities, microhardnesses, tensile strengths, and shape regaining rates of Fe-based memory alloys was investigated by means of powder sintering, with the aid of the response surface method. The results show that ball milling time, sintering temperature, and sintering time all have an important effect on alloy properties. Through the design of response surface method experiments and results analysis, a set of more accurate mathematical models could be obtained to reflect the magnitude of the influence of process parameters on the properties of the alloy and the role of the law, but also to establish the corresponding relationship between process parameters and properties. It is verified that the error between the model predicted values and the real experimental values of each performance index is 4.67% at the maximum and 0.77% at the minimum for the specimens prepared with the two sets of optimal process parameters within and outside the experimental ranges recommended by the resulting model, and the alloy compositions are controlled more accurately. The sintering and forming process of Fe-based memory alloy powder based on response surface method is instructive for engineering applications.

In order to elucidate the mechanical topological characteristics of iron powder pressing process, a numerical analysis model of iron powder pressing particles was established based on the discrete element theory, and the reliability of the model was verified by the pure iron powder pressing experiment conducted on a universal testing machine combined with the compression equation. By studying and simulating different friction factor conditions, combined with the definition of complex networks, and changing the topology-related parameters such as clustering coefficient, average degree and structural path length, the topological characteristics in the powder pressing process were explored. The results show that the number of L3 and L4 cycles composed of three and four particles increases gradually, while the number of L5, L6 and L6+ cycles composed of multiple particles decreases, indicating that the stability of the particle system is improved. In addition, the contact gap of powder particles decreases, the average degree and clustering coefficient of the system tend to decrease, and the structural path gradually becomes shorter, and the system gradually tends to densify. With the decrease of friction factor, the average degree and clustering coefficient increase, the structural path becomes shorter, and the compactness of the system is also improved, but at the same time, the fluidity becomes poor. This study reveals the evolution of the mesostructure of iron granular materials, expands the theoretical basis of the study of fine mechanics and topology of powder compression, and has guiding significance for the improvement of the dense forming of iron powder and different pressing processes.

【Objective】To accurately grasp the variation law of safety performance of lithium-ion batteries throughout their full life cycle and clarify the safety boundaries during the aging process, this study focuses on cycle-aged lithium-ion batteries, especially lithium iron phosphate (LFP) pouch cells, to explore their safety evolution mechanism under multi-dimensional abuse conditions.
【Method】Multi-dimensional abuse tests were carried out on cycle-aged lithium-ion batteries, including electrical abuse (overcharge test under mild and extreme conditions), thermal abuse (adiabatic thermal runaway test), and mechanical abuse (nail penetration and heavy impact test). Key thermal characteristic parameters were quantitatively analyzed to reveal the safety performance evolution at different aging stages.
【Result】Under mild overcharge conditions, the heat generation of batteries during overcharge decreases with deepening aging, indicating a slight improvement in safety performance. However, under extreme overcharge, the stability of aged batteries decreases significantly: thermal runaway of aged cells is triggered at around 29 V, while two-thirds of fresh cells only experience local thermal runaway at 60 V with a maximum temperature of 110 ℃, showing a notable drop in thermal runaway trigger voltage with aging. In adiabatic thermal runaway tests, the self-generated heat temperature T₁ of aged cells drops from 120 ℃ to 60 ℃, and the venting temperature of pouch cells also decreases. Under mild thermal abuse, thermal stability declines, but under extreme thermal abuse, aged batteries exhibit a higher thermal runaway trigger temperature, lower maximum thermal runaway temperature and heating rate, making thermal runaway harder to trigger. For LFP batteries under mechanical abuse (nail penetration and heavy impact), no fire or explosion occurs throughout the full life cycle, and the temperature rise decreases with aging, reflecting a slight improvement in safety.
【Conclusion】This study clarifies the full-life-cycle safety boundaries of LFP pouch batteries, providing important theoretical basis and data support for thermal runaway prevention, life management and system safety design of lithium-ion batteries. The conclusions have significant practical guiding significance for the safe application of lithium-ion batteries in energy storage and electric vehicle fields.

In this paper, the effects of laser selective melting process parameters on the forming defects, microstructure and high temperature stress rupture properties of GH3625 alloy were studied. The results show that in the process of selective laser melting, when the bulk energy density is too low, a small number of unmelted defects and more holes are observed in the metal phase. With the increase of bulk energy density, there are only a few voids in the metal phase, no incomplete fusion defects. After solution treatment, the microstructure of samples with different bulk energy density shows the morphology of transverse equiaxed crystal and longitudinal columnar crystal. The high temperature rupture life and elongation after fracture of longitudinal specimens are higher than those of transverse specimens. When there are only tiny holes in the sample, the transverse and longitudinal rupture life are more than 70 h, and the longitudinal elongation after fracture is more than 23%. The rupture fracture shows that the cracks originate from the surface of the sample. The main fracture mode of the transverse sample is that the grain boundary microcracks propagate and connect to form the main crack, and the main fracture mode of the longitudinal sample is that the grain boundary diffusion type holes gather microcracks and connect to form the main crack. The results show that the high temperature rupture life is significantly reduced when there are strip-shaped non fusion defects in the specimen, the rupture life of the transverse and longitudinal specimens is as low as 19 h and 28.7 h, respectively, and the longitudinal elongation after fracture is reduced to 9%, which is mainly because the strip-shaped non fusion defects as micro cracks accelerate the connection and propagation of the rupture crack.

The effects of annealing temperature on the microstructure, mechanical properties and tribological and wear properties of Al-Mg alloy with Er (0.14%) and Zr (0.2%) were studied by means of optical microscope, scanning electron microscope, friction and wear testing machine and tensile testing machine. The results show that with the increase of annealing temperature, the grain boundary precipitates distribute evenly, the second phase of Al₃ (Er,Zr) particles gradually increase in size, the surface columnar elongated crystals gradually fuse, and the microstructure becomes uniform. The average diameter and depth of fracture dimples gradually increase and deepen. The tensile strength and microhardness of the alloy decrease gradually, while the elongation increases gradually, and the plastic deformation ability increases significantly.

【Objective】 With the rapid development of fields such as aerospace, medical, and new energy vehicles, there arose a growing demand for the efficient and cost-effective preparation of high-performance metal powders. Therefore, this paper aimed to summarize the developmental history of numerical simulation and atomization mechanisms, reviewed advancements in gas atomization equipment, and systematically examined the effects of process parameters to promote the further development of gas atomization technology.
【Method】 A comprehensive review of recent research on gas atomization technology was conducted. The study evaluated the application of numerical simulation models, specifically examining the Volume of Fluid (VOF) model for primary atomization and the Discrete Phase Model (DPM) for secondary atomization, to elucidate the complex, high-speed fragmentation processes. Additionally, it investigated the structural designs of atomizers, focusing on the differences between free-fall and close-coupled atomizers, as well as nozzle configurations. Finally, the paper analyzed the influence of critical process parameters, including atomization gas pressure, gas temperature, melt superheat, melt stream diameter, and the gas-to-liquid mass ratio, on the final powder characteristics.
【Result】 Numerical simulations prove highly effective in visualizing unobservable phenomena, demonstrating how high-speed gas transforms metal melt into fine droplets that subsequently undergo spheroidization and solidification. Research on atomizer structures indicates that optimizing elements like the gas injection angle, delivery tube length, and nozzle aspect ratio significantly influences gas velocity and prevents nozzle blockage, thereby improving fine powder yield. Furthermore, process parameter adjustments play a pivotal role, increasing gas pressure and temperature generally enhances gas kinetic energy, leading to a reduction in powder particle size. Properly adjusting the melt superheat helps decrease surface tension and viscosity, which alters the droplet fragmentation mode and improves powder sphericity while reducing the formation of satellite particles.
【Conclusion】 The review concluded that optimizing atomizer structures and process parameters directly dictated powder quality. It also suggested that future research needed to transition from single-factor analyses to investigating the interactive effects of multiple parameters. Furthermore, future developments required the creation of continuous numerical models that seamlessly coupled primary and secondary atomization stages, as well as the utilization of big data and imaging technologies to validate simulation results.

【Objective】The increasing prevalence of “swelling” or expansion in consumer lithium-ion batteries, particularly in soft-packaged formats, poses significant challenges to product safety and lifespan. This paper aims to systematically review the current understanding of expansion in soft-package lithium-ion batteries, elucidate its underlying mechanisms, characterize its manifestations, and evaluate safety warning strategies. The objective is to provide a comprehensive theoretical foundation for developing safer consumer electronic products.
【Method】This review synthesizes findings from academic literature and public recall data. It begins by analyzing recall databases to establish the correlation between battery swelling and fire incidents. The physicochemical origins of expansion are then deconstructed into reversible and irreversible components, with a focus on gas generation, solid electrolyte interphase (SEI) layer dynamics, and electrode material degradation. Subsequently, the review examines how the unique laminated aluminum-polymer film construction of soft-package batteries influences their expansion behavior under various conditions, including external pressure and different anode materials. Finally, a critical evaluation of state-of-the-art characterization techniques (e.g., dilatometry, force sensing, electron microscopy) and their application in safety warning systems (e.g., early thermal runaway detection, state-of-health estimation) is presented.
【Result】The analysis confirms that battery swelling is a prevalent failure mode and a critical precursor to thermal runaway in consumer electronics. Irreversible expansion, driven by gas evolution from electrolyte decomposition, continuous SEI layer growth/rupture, and electrode particle fracture, is identified as the primary source of safety risk. The flexible encapsulation of soft-package cells leads to pronounced thickness increase and localized bulging, making displacement a key monitoring parameter. While traditional contact sensors and optical methods effectively measure macroscopic changes, microscopic techniques are essential for probing the root causes. Crucially, research demonstrates that signals derived from expansion characteristics—particularly the sharp rise in expansion force—offer earlier and more sensitive indicators for impending thermal runaway and internal short circuits compared to conventional voltage or temperature signals. Furthermore, a strong correlation exists between irreversible expansion and capacity fade, establishing expansion metrics as viable parameters for state-of-health (SOH) estimation.
【Conclusion】Expansion force and displacement are invaluable physical quantities for understanding battery degradation and enabling proactive safety management. Integrating these “mechanical” signals with traditional electrical and thermal data within a multi-parameter fusion framework holds immense promise for enhancing the reliability and timeliness of battery management systems (BMS). Future research should prioritize the development of integrated, in-situ “thermal-electro-mechanical” characterization tools, the establishment of standardized risk assessment protocols for swollen batteries, and the creation of predictive models that bridge the gap between micro-scale material degradation and macro-scale expansion behavior.

With the increasing demand for lightweight phase change heat sink components for high power devices, Al-based wicks demonstrate high potential for application due to their low density. Permeability and capillary force, as the key properties of porous wicks, directly influence the heat transfer performance of heat sink components. However, due to the limitation of testing methods, the effect of powder properties on permeability and capillary force has rarely been reported. In this paper, Al-based porous wicks are prepared by a loosely packed sintering process, using Al powders of different sizes and morphologies with suitable flux. The differences between pore characteristics, permeability and capillary properties, and flexural strength of the porous wicks are compared in detail, which reveal their relationship with Al powder size and morphology. The results show that powder size and morphology have a significant effect on the pore characteristics of wicks. Using the irregularly shaped 180-106 μm Al powder, the porous wick can maintain high porosity while possessing high strength, which exhibits the best overall performance, with a porosity of 40.84%, a permeability of 2.94×10^-11 m², a capillary force of 0.92 kPa, and a flexural strength of 26.05 MPa.

【Objective】0.5-20 μm ultrafine metal powders are of significant application value in the metal injection molding (MIM) field, but traditional methods such as gas atomization and plasma atomization struggle to achieve a high yield in the 0.5-20 μm range. Constraining the plasma atomization flow field in physical space has been proven to be an effective approach to improve the yield of 0-20 μm powders. However, the mapping relationship between the constraining nozzle structure and the particle size distribution remains unclear, hindering further improvement in the yield of this specific powder fraction. Therefore, this study aims to investigate the influence of the constraining nozzle structure on the particle size distribution.
【Method】This paper employs computational fluid dynamics (CFD) simulation to investigate the influence of the constraining nozzle structure on the particle size distribution within the flow field of In-flight Droplet Plasma Atomization (IDPA), and conducts experiments on the influence of Laval nozzles with different throat diameters on particle size. To comparatively verify the advantage of IDPA technology in improving the yield of ultrafine metal powders, parallel experiments of conventional Plasma Atomization (PA) powder production were conducted under identical process parameters.
【Result】All powders prepared by the IDPA method has particle sizes smaller than 50 μm, with the majority exhibiting regular spherical morphology. Among them, the TC4 powder prepared using a Laval nozzle with a throat diameter of 8 mm shows the smallest D₁₀ and D₅₀ values, 5.7 μm and 13.7 μm respectively, while the powder obtained from the nozzle with a 10 mm throat diameter has the largest D₁₀ and D₅₀ values, 6.8 μm and 14.4 μm respectively. The powders prepared by nozzles with three different throat diameters all have D₉₀ values around 24 μm, and the proportion of ultrafine powder is approximately 80%. In contrast, powders prepared by the PA method exhibite a wider particle size distribution, with significantly larger D₁₀, D₅₀, and D₉₀ values of 46.0 μm, 79.4 μm, and 137.1 μm respectively, and almost no ultrafine particles are smaller than 20 μm.
【Conclusion】(1) The velocity spatial gradient in the flow field at the nozzle throat is the key factor affecting particle size distribution. Increasing this gradient can significantly reduce the D₁₀ and D₅₀ values of the powder. This gradient is primarily regulated by the throat diameter, with a smaller diameter leading to a larger gradient.(2) Reducing the throat diameter of the Laval nozzle effectively decreases the D₁₀ and D₅₀ of the produced powder. A throat diameter of 8 mm resulted in the smallest D₁₀ and D₅₀ values (5.7 μm and 13.7 μm, respectively) for TC4 powder compared to diameters of 9 mm and 10 mm. Furthermore, the TC4 powders prepared by IDPA all exhibited a regular spherical morphology, and the coarse powder size remained stable, with D₉₀ consistently around 24 μm, indicating that the throat diameter primarily regulates the proportion of ultrafine powder rather than the upper limit of coarse powder size.(3) Experiments show that the proportion of ultrafine powder in the powders prepared by the IDPA method remain stable at approximately 80% across different throat diameters, indicating that the ultrafine powder yield is insensitive to throat size variations. Comparative experiments with the PA method further confirm that, under identical process parameters, the yield of ultrafine metal powder by the IDPA method is significantly higher than that by the PA method.

Iron-based amorphous coatings were fabricated by high-velocity oxy-fuel (HVOF) spraying. The effects of oxygen flow rate and powder feed rate on the average thickness per layer, porosity, and Vickers hardness of the coatings were systematically investigated. The average thickness per layer was mainly affected by the combustion degree between aviation kerosene and oxygen, as well as by the powder feeding rate. When the oxygen flow was 0.849 6 or 0.873 2 m³/min, i.e., close to the complete combustion ratio between oxygen and kerosene, the coating exhibites the highest average thickness per layer. With further increase in oxygen flow, the average thickness decreases, whereas it increases gradually with increasing powder feeding rate. The porosity of the coatings is jointly affected by the surface oxidation of powder particles and by their temperature and velocity, which are influenced by the heating and acceleration effects of the combustion gas during spraying. No clear mathematical relationship is found between porosity and powder feeding rate. As oxygen flow increases, porosity first increases and then decreases, reaching a peak at 0.896 8 m³/min. The micro-Vickers hardness of the coatings is mainly determined by the thermal input to the powder particles from the high-temperature, high-velocity gas flow. Higher thermal input led to lower hardness. Increasing the powder feeding rate also reduces the hardness. With increasing oxygen flow, the microhardness first decreases and then increases, eventually reaching the lowest value at 0.873 2 m³/min. Given the result of porosity examination, the optimal process parameters are determined as an oxygen flow of 0.849 6 m³/min and a powder feeding rate of 3.8 g/min, under which the coating exhibites the lowest porosity (1.8%), an average single-layer thickness of 21.4 μm, and a Vickers hardness of 810.8 HV.

Multi-metal laser additive manufacturing is an emerging technology for manufacturing complex parts with excellent overall performance. In this study, mutant functional gradient materials with 100% compositional change of Ti65/Q355D were prepared by laser direct energy deposition. Microstructure analysis, energy spectrum analysis, transmission electron microscopy analysis, microhardness and friction property tests were used to characterize and analyze the microstructure evolution, compositional segregation, microcrack formation and mechanical properties of the materials. The results show that the microstructures of Ti65 and Q355D are dominated by columnar dendrites and equiaxed dendrites, respectively. The compositional segregation of Ti65 on the Q355D side is induced by Marangoni convection effect, and the compositional segregation of the two metals and the different physical properties of the two metals are the main reasons for the inclined cracking near the interface. The two metals diffused each other at high temperatures, and the microhardness increases nearly linearly from Q355D (163HV) to Ti65 (529 HV). The wear surface of Q355D is caused by the combination of abrasive, adhesive wear and micro-cutting, resulting in grooves, chips, spalling and micro-cracks. The wear surface of Ti65 containes fine debris and smooth shallow grooves, resulting in abrasive wear and slight adhesive wear. Deposition of Ti65 on the surface of Q355D can significantly improve the microhardness and friction and wear properties of the specimens, providing data support for the practical application of gradient materials.

In this paper, by changing the time of aging treatment, comparative study of aging treatment on the organization and tensile properties of selective laser melting (SLM) forming AlMgScZr alloy, analysis of the organization morphology and tensile properties of the trend of change, for the SLM AlMgScZr heat treatment process to provide data reference and theoretical support. The results show that after aging treatment for 2, 4 and 6 h, the tensile strength of the alloy reaches 507.9, 538.5 and 575.4 MPa, which are increased by 35%, 43% and 52%, respectively, compared with that of the alloy without aging treatment, this is due to the fact that the alloy precipitates a large number of precipitated phases with the increase of aging treatment time, and the increase of Al₃(Sc,Zr) content, which hinders the dislocation movement and produces precipitation strengthening and fine grain strengthening. A large number of tough nests are present in the fracture morphology of the alloy, and the content of cleavage surfaces increases with aging treatment time.

Fe-based powder metallurgy oil-bearing materials trend to can't simultaneously have both high mechanical properties and good self-lubricating properties, which seriously hinders the development and application of Fe-based oil-bearing. Reinforcement phase, lubrication phase, preparation process and pore structure are depicted to briefly describe Fe-based powder metallurgy oil-bearing materials. It is shown that the development of a kind of Fe-based powder metallurgy oil-bearing materials with good lubrication and high mechanical properties is one of the future development trends of Fe based composite materials.

【Objective】To accurately estimate the state of charge (SOC) of lithium-ion batteries and overcome the limited adaptability of single estimation algorithms under driving cycle.
【Method】A dual-timescale SOC estimation method based on a voltage residual weighted fusion algorithm is proposed. First, online parameter identification is performed using a Thevenin equivalent circuit model combined with the forgetting factor recursive least squares (FFRLS) method to capture battery dynamics across micro and macro timescales. Then, preliminary SOC estimates are obtained using extended Kalman filter (EKF) and H-infinity filter (HIF). To address the issues of large error fluctuations and multi-scale requirements inherent in single algorithms, a voltage residual weighted fusion (RWF) strategy is introduced, and the weight coefficients are optimized through dual-timescale collaborative optimization.
【Result】The proposed dual-timescale voltage residual weighted fusion algorithm (T-RWF) achieves a SOC estimation error of less than 1.082%, while exhibiting excellent robustness and computational efficiency.
【Conclusion】The method significantly enhances SOC estimation accuracy and adaptability under driving cycle, offering a reliable and efficient solution for battery management systems.

The titanium coatings were prepared by mechanical coating technology on the surface of ZrO₂ balls with 1mm diameter,and then the titanium coatings were oxidized to titanium oxide coatings at 500 ℃ for 5 h. The cross-section morphology of titanium coatings were analyzed by metallographic microscope, and then the influence of different milling speed and milling time on the formation of coatings were studied. The phase composition of titanium oxide coatings were analyzed by X-ray diffractometer (XRD), and the photocatalytic properties of different coating thicknesses and different coating dosages were measured. The results show that the increase of ball mill speed will increase the energy input of ball mill system per unit time, thus increasing the deposition rate of powder material and thickening the coatings. In a certain range of milling time, the coating thickness increases with the increase of milling time, and the photocatalytic performance of the coating increases with the increase of the coating thickness, and finally tended to be stable. The increase of catalyst dosage will increase the degradation rate of solution, but too much catalyst dosage will decrease the degradation rate of solution. The best photocatalytic performance of the coatings is 88.4% when the milling time is 30 h and the dosage is 1 g/mL. And the coatings have a good reusability.

【Objective】This study investigated the recovery of iron from pyrite cinder using a direct reduction-magnetic separation process, with an emphasis on clarifying the effects of bitumite coal (bitumite) dosage, CaO dosage, reduction temperature, and reduction time on the total Fe grade and iron recovery of the direct reduced iron (DRI).
【Method】A four-factor, three-level orthogonal experimental design was employed to evaluate the effects of the four parameters on the total Fe grade and iron recovery of DRI. The pyrite cinder, bituminous coal, and CaO were thoroughly mixed and then placed in a graphite clay crucible. The crucible was introduced into the muffle furnace once the preset temperature was reached, and then roasting was conducted for the designated time to obtain the roasted product. The roasted product was ground and then subjected to magnetic separation to obtain a magnetic DRI.
【Result】The orthogonal experimental results indicate that during direct reduction, the factors affecting the total Fe grade of DRI follow the order of significance: CaO dosage > bitumite dosage > reduction temperature > reduction time. In contrast, the order of their influence on iron recovery is: bitumite dosage > CaO dosage > reduction temperature > reduction time. A mixture composed of 100% pyrite cinder, 30% bitumite, and 10% CaO was roasted at 1 200 ℃ for 60 min. Under the optimal conditions of a grinding fineness (with -0.074 mm fraction content) of 51.66% and a magnetic field intensity of 0.10 T, a DRI with total Fe grade, iron recovery and S content of 90.22%, 92.17% and 0.27%, respectively, was obtained.
【Conclusion】The process of direct reduction-magnetic separation proved to be effective for recovering iron from pyrite cinder. Under the optimized reduction parameters and subsequent grinding and magnetic separation conditions, a DRI product with high total Fe grade, high iron recovery, and low sulfur content was successfully obtained, demonstrating a viable strategy for the comprehensive utilization of pyrite cinder.

【Objective】 In response to the application requirements of additive manufacturing (AM) technology for metallic lattice-structured components, this paper clarifies the key technical points and research progress of AM in fabricating metallic lattice structures, investigates the critical issues in the forming, property regulation and defect control of such components, and provides theoretical references and research insights for the technological development and engineering application of additively manufactured metallic lattice-structured components.
【Method】 Using literature investigation and comprehensive analysis, this work systematically reviews the development history and application status of additively manufactured metallic lattice-structured components, focuses on the classification and characteristics of lattice structures, and expounds the technical advantages of additive manufacturing for fabricating lattice structures. From a metallurgical perspective, it analyzes the dynamic process of powder melting and solidification during the lattice structure forming procedure, investigates the regulation mechanism of heat treatment on the mechanical properties of the components, comprehensively summarizes the defect formation mechanisms of metallic lattice structures, and sorts out the mainstream defect detection methods at the current stage.
【Result】 The structural characteristics and differences in mechanical properties of three types of lattice structures (truss-type, triply periodic minimal surface (TPMS), and bionic-type lattices) are clarified. Additive manufacturing is confirmed to exhibit prominent advantages in the fabrication of metallic components with complex lattice structures, such as high design flexibility, large forming freedom, and the ability to realize the synergistic optimization of lightweight and performance. The influence laws of micro-melt pool characteristics, remelting phenomena and process parameters on the forming quality of lattice structures are revealed. The coupling relationships between heat treatment processes, microstructures and mechanical properties of lattice structures with different matrix materials are analyzed. The common defects and corresponding formation mechanisms of additively manufactured metallic lattice-structured components are summarized, and industrial computed tomography (CT) integrated with intelligent algorithms is identified as an efficient approach for the defect detection of lattice structures at the current stage.
【Conclusion】 Additive manufacturing provides an effective approach for the fabrication of complex metallic lattice structures. Benefiting from the advantages of high specific strength, high specific stiffness, lightweight and multifunctionality, metallic lattice‑structured components present broad application prospects in aerospace, medical treatment, automotive engineering and other fields. Among these aspects, the regulation of the melting and solidification process during additive manufacturing, the optimization of heat treatment processes, and defect detection and control are the key links to improve the forming quality and performance of additively manufactured metallic lattice‑structured components. For the future development of additive manufacturing technology for metallic lattice‑structured components, efforts should be focused on the multi‑scale optimal design of lattice structures, the investigation of the metallurgical essence of additive manufacturing, the construction of the full‑cycle manufacturing process, and the full exploitation of AM technical advantages, so as to promote the engineering application of this technology in high‑end equipment manufacturing and other fields.

【Objective】 This study aims to address the critical issue of microcrack formation during the selective laser melting (SLM) of GH3230 superalloy. The primary objective is to optimize the SLM process parameters and systematically investigate the synergistic effects of hot isostatic pressing (HIP) and subsequent heat treatment (HT) on the microstructure evolution and mechanical properties of the alloy, thereby providing a feasible processing strategy for the high-quality SLM formation of GH3230 superalloy.
【Method】 Spherical GH3230 superalloy powder prepared via the high-speed plasma rotating electrode process (SS-PREP) was used as the raw material. The SLM process was conducted by adjusting the laser power to screen the optimal parameters with minimal microcracks. Three groups of samples were prepared: as-SLM, HIP-treated, and HIP+HT-treated. The microstructures were characterized using optical microscopy (OM), scanning electron microscopy (SEM), and X-ray diffraction (XRD). The mechanical properties were evaluated by tensile tests at both room and high temperatures, and the fracture mechanisms were analyzed via fractography.
【Result】 Low laser power results in insufficient energy density and subsequent lack-of-fusion defects, while the parameter of 205 W effectively reduces microcracks and eliminates unmolten defects. After HIP treatment, all microcracks in the as-SLM state are fully closed. Chain-like carbides are precipitated continuously along both grain boundaries and intragranular regions, with an average size of 1.31 μm and an equivalent grain diameter of 7.14 μm. Following HIP+HT treatment, the carbides underwent remelting and redistribution, reducing their average size to 1.18 μm, while the grain size increases by 32.1% compared to the HIP state. This microstructural evolution lead to a decrease in room-temperature tensile strength due to the weakening of precipitate strengthening, but a synergistic enhancement in high-temperature tensile strength and plasticity is achieved via refined grain boundary carbides and grain coarsening. Fracture analysis reveals that the HIP+HT state exhibites quasi-cleavage fracture at room temperature and ductile fracture at high temperatures.
【Conclusion】 The 205 W laser power parameter effectively mitigates microcrack and lack-of-fusion defects in SLM-fabricated GH3230 superalloy. HIP treatment achieves full crack closure and uniform carbide precipitation, while HIP+HT further optimizes the microstructure by regulating carbide distribution and grain growth. The HIP+HT-treated alloy exhibits a balanced combination of reduced room-temperature strength and improved high-temperature mechanical properties, which is attributed to the cooperative effects of refined carbides and grain coarsening. These findings provide critical technical guidance for the industrial application of SLM-fabricated GH3230 superalloy in high-temperature service environments.

【Objective】Powder bed fusion-laser beam (PBF-LB) can efficiently fabricate alloy parts with high relative density and complex structure, presenting good application potentials in the aerospace, biomedicine and transportation fields. Al-series alloy is one of the commonly-applied materials in PBF-LB, such as Al-Cu alloy with good mechanical strength and heat resistance. However, during nonequilibrium solidification of PBF-LB, the insufficient element diffusion and abundant defects easily result in the brittle intermetallic compounds (IMCs) precipitated at grain boundaries continuously. It would weaken the interface bonding strength, thus decreasing the plastic deformability and inducing the brittle fracture. Nowadays, heat treatment is a key approach ameliorating the PBF-LB-formed microstructure segregation, by utilizing IMCs dissolution-precipitation behaviors and grain recrystallization-growth mechanisms. Commonly, the strength and ductility properties show the opposite evolution laws along the varied microstructure. Therefore, studying the appropriate treatment regime for the specific-series alloy and its influence on the microstructure is essential for achieving mechanical properties trade-off. This work attempted to improve the strength-ductility properties of a novel PBF-LB-fabricated Al-Cu-Ni-Mg-Si alloy synchronously, by validating the influence of heat treatment on the microstructure. Herein, only the solid solution approach was utilized to coordinate the relationship between the strengthening effect and plastic deformability.
【Method】The gas-atomized Al-Cu-Ni-Mg-Si alloying powders were served as raw materials, and the PBF-LB equipment (EP-M150) was employed to fabricate alloy specimen layer by layer (Fig.1). The key parameters included the laser power of 240 W, scanning speed of 600 mm/s, hatch space of 180 μm, layer thickness of 30 μm and rotation angle of 67°. After then, the as-fabricated specimens were treated in an electric furnace (SX-B01123), and the related solid-solution temperature was designed based on the Differential Scanning Calorimetry (DSC) thermal analysis. The defect morphology was examined on the Optical Microscopy (OM) and Scanning Electron Microscopy (SEM) instruments. And, the microstructure and element distribution were characterized by SEM and Transmission Electron Microscopy (TEM) equipped with Energy Dispersive X-ray Spectroscopy (EDS). Besides, the grain information was obtained by the Electron Backscatter Diffraction (EBSD) detection. To evaluate the mechanical properties, the tensile tests and Vickers hardness tests were conducted. Through the synthetic analysis of microstructure and mechanical properties, their relationships were validated to select the appropriate treatment regime and optimize the strength-ductility properties.
【Result】DSC curves of the PBF-LB-fabricated Al-Cu-Ni-Mg-Si alloy present three endothermic peaks (533 ℃, 587 ℃ and 639 ℃), representing the melting behaviors of different IMCs (Fig.2). On the basis, the heat treatment temperature was designed. When the temperature is over 510 ℃, the serious pore defects are generated due to the overburning effect of IMCs (Fig.3). Under 480-495 ℃, the microstructure homogeneity and relative density are obviously improved, primarily contributed by the promoted diffusion of atoms and vacancies under high temperature. The grain-boundary IMCs including Al₂Cu, Al₇Cu₄Ni and Mg₂Si, undergo the nodulizing, dissolving and coarsening process during treatment (Figs.4,5). The partially-dissolved submicron particles were still present at 480 ℃, whereas most of them were dissolved and only a few particles with higher melting point were coarsened. Newly-formed nano-sized particles were also observed, mainly induced by the precipitation reaction of the supersaturated solid solution during nonideal heating or cooling process. Besides, the columnar grains in the as-printed alloy become much coarser which grow up to over 40 μm due to the recrystallization effects (Figs.6). Under the microstructure features above, the mechanical properties and failure modes were regulated (Figs.7,8). The as-printed alloy shows the ultimate tensile strength (UTS), yield strength (YS) and elongation rate (EL) of 438.5 MPa, 340.4 MPa and 10.4%, respectively (Table 3). Due to the continuous aggregation of IMCs phase at grain boundary, the brittle fracture morphology is presented under as-printed state. After solid solution, the failure mode transforms into the ductile fracture completely. Particularly, the alloy treated at 480 ℃-1 h can maintain the YS at 340.3 MPa, meanwhile shows the improved UTS of 485.3 MPa and EL of 15.0%. The ductility is significantly improved by the reason that the precipitate density decreased and the matrix grains coarsened. Whereas, the partially-dissolved IMCs can enhance the solid-solution strengthening effect, and the nano-sized phase can pin up dislocations to promote working hardening rates, thus avoiding the degradation of mechanical strength.
【Conclusion】The strength-ductility properties of the PBF-LB-fabricated Al-Cu-Ni-Mg-Si alloy were synergically optimized through solid solution treatment. The ultimate tensile strength and elongation rate were improved from 438.5 MPa and 10.4% to 485.3 MPa and 15.0% under the treatment regime of 480 ℃-1 h, respectively. Meanwhile, the yield strength shows no obvious degradation (340.3 MPa). The optimization was primarily determined by the microstructure features of IMCs precipitates and matrix grains. As validated by the DSC tests and physical characterizations, it can be known that high-temperature (≥510 ℃) treatment would bring out the overburning phenomenon, thus causing the high-proportion pore defects. Decreasing the temperature to 480-495 ℃ can improve relative density of the as-printed alloy, meanwhile improve the distribution homogeneity of precipitate phase and restrain its coarsening degree. Under the synergic effects of the microstructure features including the partially-dissolved precipitates, nano-sized precipitates and recrystallized columnar grain, the balance between the strengthening mechanism (solid solution, precipitate and grain boundary strengthening) and plastic deformability was achieved.

【Objective】 This study aims to investigate the constitutive behavior of solution-treated FGH95 nickel-based superalloy during the continuous cooling process, with a focus on the precipitation of the secondary γ' phase and its influence on mechanical properties. The objective is to clarify the relationship between thermal history, γ' precipitation evolution, and mechanical response, and to establish a constitutive model capable of describing the material behavior during non-isothermal cooling.
【Method】 Solution-treated FGH95 alloy specimens were prepared by holding at 1 180 ℃, cooling uniaxial tensile tests were conducted under two different thermal paths, namely direct heating from room temperature and cooling interruption from the solution temperature, at temperatures ranging from room temperature to 1 000 ℃. Tension-compression cyclic tests were also performed to investigate the hardening behavior. Microstructural characterization was carried out using scanning electron microscopy under different cooling rates. Thermodynamic calculations and precipitation simulations were performed using JMatPro and MatCalc to analyze phase evolution. Based on experimental observations, a constitutive model incorporating dislocation slip resistance and precipitation strengthening was established, in which the evolution of the secondary γ' phase volume fraction was described by the JMA equation. Model parameters were calibrated by fitting experimental stress-strain curves.
【Result】 The results show that γ' phase precipitation during continuous cooling at 20 ℃/min is inevitable and mainly occurs within a high-temperature range. Compared with the direct heating condition, the specimens subjected to cooling exhibit higher yield strength and strain hardening rate at the same temperature. This difference is caused by the distinct thermal histories prior to deformation, which result in different stages of secondary γ' precipitation. During cooling from 1 180 ℃, a significant amount of secondary γ' phase has already precipitated before deformation, whereas only limited precipitation occurs during heating from room temperature. In addition, the precipitation of γ' phase continues during deformation at elevated temperatures, further enhancing strain hardening. Microstructural observations confirm that lower cooling rates promote the formation of coarser γ' precipitates, while higher cooling rates lead to finer and more densely distributed secondary γ' particles. The proposed constitutive model accurately captures the evolution of flow stress under both heating and cooling conditions and reflects the contribution of precipitation strengthening.
【Conclusion】 The constitutive behavior of solution-treated FGH95 superalloy during continuous cooling is strongly dependent on the evolution of the secondary γ' phase. The difference in mechanical properties between heating and cooling conditions originates from the distinct precipitation states induced by thermal history. The developed constitutive model, which incorporates precipitation evolution based on the JMA framework, can effectively predict the mechanical response during continuous cooling and provides a useful tool for analyzing microstructure-property relationships and optimizing heat treatment processes.

【Objective】The escalating demand for high-energy-density power sources has propelled lithium-rich manganese-based layered oxides into the spotlight as preeminent cathode candidates for advanced lithium-ion batteries, primarily attributable to their exceptional specific capacities surpassing 250 mAh/g. Despite this advantage, widespread practical implementation remains elusive due to pronounced capacity fading, continuous voltage decay, and inferior high-rate performance upon extended electrochemical cycling. These detrimental phenomena stem from progressive structural transformation, cation migration within the lattice, and parasitic side reactions at the electrode/electrolyte interface. This investigation explores tellurium incorporation as a modification strategy to concurrently reinforce the crystallographic framework, improve interfacial characteristics, and elevate the overall electrochemical behavior with emphasis on long-term cyclability and high-rate capability.
【Method】Te-substituted Li-rich cathode materials were fabricated through a solid-state reaction protocol employing carbonate-based precursors. Initially, a spherical (Mn_0.60Ni_0.30Co_0.10)CO₃ precursor with homogeneous elemental distribution was obtained via controlled co-precipitation from transition metal sulfate solutions. This intermediate product was subsequently homogenized with lithium carbonate and telluric acid in stoichiometric proportions, followed by thermal treatment under optimized conditions to yield the final doped compounds. Comprehensive structural interrogation was performed utilizing powder X-ray diffraction with Rietveld refinement to extract precise crystallographic parameters. Morphological evolution and microstructural features were examined through scanning electron microscopy. Electrochemical characterization involved galvanostatic charge-discharge measurements within a 2.0-4.65 V potential window. Cycling durability was evaluated over 300 consecutive cycles at 1 C, while rate performance assessment spanned current densities from 0.1 C to 10 C. Electrochemical impedance spectroscopy provided insights into interfacial charge transfer phenomena throughout cycling.
【Result】Rietveld analysis of diffraction patterns verifies the successful lattice incorporation of Te⁶⁺ species, which induces measurable expansion of unit cell dimensions attributable to ionic radius disparities. Post-cycling morphological examination reveales that Te-modified specimens retain superior particle integrity with markedly fewer intergranular fissures compared to undoped counterparts, indicating effective retardation of mechanical degradation. Electrochemical testing demonstrats that the composition containing 1% Te exhibites substantially improved capacity retention reaching 85.74% after 300 cycles at 1 C, markedly exceeding the 54.32% observed for the pristine material. Furthermore, the doped electrode delivers 158.3 mAh/g at 10 C, significantly surpassing the 138.1 mAh/g obtained from undoped samples. Impedance analysis reveals that Te incorporation effectively mitigates the progressive increase in charge transfer resistance during extended cycling, indicative of enhanced interfacial stability and facilitated lithium-ion transport.
【Conclusion】Tellurium doping emerges as an efficacious approach for reinforcing the structural robustness and interfacial properties of lithium-rich manganese-based layered cathode materials. The expanded lattice parameters coupled with diminished cation mixing effectively suppress cycling-induced structural deterioration, while the stabilized electrode/electrolyte interface promotes favorable charge transfer kinetics. These synergistic effects collectively contribute to substantially improved cyclic stability and rate performance. This investigation presents a viable pathway for developing high-performance cathode materials through judicious doping strategies coupled with interface engineering considerations.

【Objective】Relaxor ferroelectric polymers, distinguished by their unique polar nanodomain structures, combine high dielectric constant, low energy loss, mechanical flexibility, and electrochemical stability, positioning them as promising functional materials for advanced lithium batteries. Unlike conventional ferroelectrics, their nanoscale polar regions enable rapid response and efficient energy storage under external electric fields, with minimal remanent polarization and hysteresis loss. This allows them to effectively modulate interfacial electric fields in batteries without introducing additional energy dissipation. This review aims to systematically examine the material evolution, design strategies, and functional mechanisms of relaxor ferroelectric polymers in lithium battery applications, with a focus on their role in enhancing electrochemical performance through multi-interface regulation.
【Method】The paper first traces the development of relaxor ferroelectric polymer systems, emphasizing molecular level design strategies such as chemical defect incorporation to disrupt long-range ferroelectric ordering and branching/cross linking approaches to simultaneously improve mechanical properties and ionic transport. Subsequently, it reviews the application of these materials in lithium batteries, analyzing their effects on electric field distribution at the cathode interface, carrier dissociation within the electrolyte bulk, and lithium deposition uniformity at the anode. By synthesizing existing research, this review further explores the structure property relationships governing electrochemical performance and identifies key challenges hindering large scale deployment. Future research directions are outlined by integrating material science, electrochemistry, and advanced characterization techniques.
【Result】The review reveals that relaxor ferroelectric polymers effectively modulate multi-interface electrochemical environments, leading to enhanced energy density, rate capability, and cycling stability of lithium batteries. At the cathode, their polar nanodomains facilitate local field enhancement, promoting lithium-ion migration and charge transfer. Within the electrolyte, the polar regions contribute to carrier dissociation and transport, reducing interfacial impedance. At the anode, uniform electric field distribution effectively suppresses lithium dendrite growth. Despite these laboratory scale advantages, several bottlenecks remain, high synthesis costs limit scalable production, poor processing compatibility hinders integration with existing battery manufacturing, long term cycling reliability under realistic conditions is insufficiently understood and the multi field coupling mechanisms require further investigation, particularly the interplay among electric field, mechanical stress, and electrochemical behavior.
【Conclusion】Relaxor ferroelectric polymers hold substantial promise for next generation lithium batteries, yet their translation from laboratory breakthroughs to practical applications requires targeted efforts. Future work should prioritize the development of fluorine-free systems to mitigate environmental and safety concerns, alongside multi-scale structural control to optimize dielectric and mechanical properties. For mechanism studies, combining in-situ characterization with machine learning will be essential to resolve polarization transport coupling and reveal material evolution under real operating conditions. Expanding their application scope to all solid state batteries and flexible energy storage devices will further accelerate industrial adoption. Through synergistic advances in material innovation and engineering optimization, relaxor ferroelectric polymers are poised to achieve the critical transition from laboratory research to practical implementation.

【Objective】The rapid advancement of electric vehicles and energy storage technologies has heightened the demand for high-safety lithium-ion batteries. Conventional liquid electrolytes are volatile, flammable, and thermally unstable, posing severe safety risks under extreme conditions. Solid-state electrolytes, particularly polymer-based systems, offer enhanced thermal stability, mechanical robustness, and improved interfacial compatibility. This review aims to systematically summarize recent progress in polymer solid-state electrolytes for high-safety lithium-ion batteries, with a focus on their safety enhancement mechanisms, initiator-based in situ polymerization strategies, and self-polymerizing electrolyte systems.
【Method】This review surveys the literature on polymer solid-state electrolytes, emphasizing three key aspects: (1) The fundamental mechanisms by which polymer electrolytes improve battery safety, including thermal stabilization, lithium dendrite suppression, and interfacial stabilization. (2) The design and application of initiator-based in situ polymerization systems, categorized into thermal, photo, and redox initiation methods. (3) Emerging self-polymerization approaches that operate without external initiators, including lithium salt-induced ring-opening polymerization and electrochemically triggered polymerization.
【Result】Polymer solid-state electrolytes significantly mitigate thermal runaway risks through multiple synergistic mechanisms. The incorporation of thermally stable polymer backbones, functional groups , and three-dimensional crosslinked networks enhances thermal stability and flame retardancy. High mechanical modulus and anion-immobilizing structures effectively suppress lithium dendrite growth. In situ polymerization using thermal initiators or photoinitiators enables the formation of intimate electrode/electrolyte interfaces, improving cycling stability and delaying thermal runaway. Self-polymerizing systems, such as LiPF₆-induced ring-opening polymerization of 1,3-dioxolane, achieve high ionic conductivity and stable interface formation without exogenous initiators, simplifying fabrication and enhancing safety.
【Conclusion】Polymer solid-state electrolytes represent a promising pathway toward high-safety lithium-ion batteries. While significant progress has been made in enhancing ionic conductivity and interfacial stability through in situ and self-polymerization strategies, challenges remain in precisely controlling the reactivity of liquid precursors prior to polymerization. Future research should focus on developing low-reactivity, high-stability precursors that can be polymerized under mild conditions after cell assembly, thereby improving both safety and processability for practical applications.

【Objective】Diamond/Cu composites have attracted extensive interest as advanced thermal management materials owing to the combination of the ultrahigh thermal conductivity of diamond and the ductility of copper. Although interfacial modification and reinforcement parameters have been widely explored, the influence of matrix powder morphology on microstructural evolution and property development during sintering at different temperatures remains insufficiently clarified. In this work, the influence of copper powder morphology on densification behavior, mechanical properties, thermal conductivity, and microstructural evolution of diamond/Cu composites was investigated under identical composition and pressure conditions over a series of sintering temperatures.
【Method】Two commercially available high-purity copper powders with different particle morphologies were used as matrix materials, including an electrolytic dendritic powder and an atomized spherical powder. Chromium-coated diamond particles with a fixed volume fraction were incorporated as reinforcement. Composite specimens were consolidated by vacuum hot-press sintering under controlled pressure within the typical processing window of Cu-based systems. Relative density was determined using the Archimedes method. Flexural strength was evaluated through three-point bending tests. Thermal diffusivity and specific heat were measured by laser flash analysis to calculate thermal conductivity. Fracture morphology, pore distribution, and interfacial characteristics were characterized by scanning electron microscopy, energy-dispersive spectroscopy, and X-ray diffraction. Theoretical thermal conductivity was further predicted using a differential effective medium model considering interfacial thermal resistance derived from acoustic mismatch theory.
【Result】Sintering temperature influences densification and property evolution in both composite systems. With the increase of the temperature, relative density and thermal conductivity first increase and then decrease, reflecting the competition between improved diffusion bonding and copper exudation at elevated temperatures. Copper powder morphology modifies this temperature-dependent behavior. Composites fabricated with dendritic electrolytic copper powder maintain more stable densification across the investigated temperature range and exhibit reduced copper overflow at high temperature. Although their relative density is moderately lower than that of spherical powder-based counterparts at certain intermediate temperatures, their flexural strength is consistently higher, reaching an average value of approximately 195 MPa, corresponding to an increase of about 32%. The dendritic matrix structure forms a more interconnected framework and results in distributed micro-scale porosity, which promotes crack deflection and localized plastic deformation during fracture. Thermal conductivity shows a similar non-monotonic dependence on sintering temperature for both systems, with a maximum value of 228 W/(m·K) obtained for the dendritic powder-derived composites. However, the experimentally measured values remain below 60% of the theoretical prediction from the differential effective medium model. This result indicates that interfacial thermal resistance plays the dominant role in limiting heat transfer, whereas variation in copper powder morphology has a relatively minor influence on intrinsic thermal conduction.
【Conclusion】The performance evolution of diamond/Cu composites results from the combined effects of sintering temperature and matrix powder morphology. While interfacial thermal resistance remains the primary factor limiting thermal transport efficiency, copper powder morphology significantly affects temperature stability, fracture behavior, and processing robustness. Under identical fabrication conditions, electrolytic dendritic copper powder provides improved mechanical reliability and more stable sintering performance over the investigated temperature range. These findings provide insight into matrix material selection and process optimization for high-performance diamond/Cu thermal management composites.

【Objective】 With the continuous progress of aerospace, nuclear energy and other high-end strategic industries, additive manufacturing and other advanced forming technologies put forward stricter demands for the overall performance of refractory metal raw powder. High-sphericity, good-fluidity and high-apparent-density molybdenum powder is the key foundation for high-quality forming of molybdenum alloy parts. To solve the bottleneck of high-performance spherical molybdenum powder mass preparation, this work aims to adopt DC arc plasma spheroidization technology to modify commercial irregular molybdenum powder, explore the influence rules of key process parameters on powder comprehensive performance, and reveal the intrinsic spheroidization mechanism, so as to provide technical basis for industrial mass production and high-end engineering application of spherical molybdenum powder.
【Method】 Commercial irregular molybdenum powder was selected as the experimental raw material, and DC arc plasma spheroidization equipment was used for powder modification treatment. Focusing on two critical process parameters including powder feeding rate and plasma power, comparative experiments with different parameter combinations were carried out. Multiple testing devices were applied for multi-dimensional characterization: scanning electron microscope was used to observe powder microscopic morphology, X-ray diffraction was adopted to analyze phase composition changes, and special testing instruments were utilized to detect particle size distribution, powder flowability and apparent density of samples before and after spheroidization.
【Result】 DC arc plasma treatment would not change the phase structure of molybdenum powder, and the spheroidized powder still presents single body-centered cubic molybdenum phase without oxide impurities or miscellaneous phases. The optimal process parameters are determined as powder feeding rate of 80 g/min and plasma power of 45 kW. Under this condition, the powder spheroidization rate is over 98%, with smooth particle surface and no obvious agglomeration. Compared with raw powder, the particle size distribution become more uniform, the median particle size decreases from 34.47 μm to 23.56 μm. Meanwhile, the powder flowability and apparent density are greatly improved, among which the flowability is optimized to 11.6 s/50g, and the apparent density increased by 117.9%.
【Conclusion】 DC arc plasma technology is highly applicable and reliable for the spheroidization modification of molybdenum powder. The whole spheroidization process can be summarized as three stages of energy absorption, droplet formation and solidification stabilization. Excessively high plasma power will induce nanoparticle coating on powder surface, which has potential application value in functional modification. The optimized process parameters obtained in this study can effectively improve the sphericity, flowability and bulk density of molybdenum powder, which is conducive to the popularization and application of high-performance spherical molybdenum powder in advanced powder forming fields.

As the price of lithium carbonate decreases, the unsprayed lithium iron phosphate (LFP) electrode slices turn into black powder, which poses significant cost pressure for the wet recovery and extraction of lithium carbonate and iron phosphate products. Therefore, regenerating and repairing LFP cathode materials from unsprayed LFP electrode slices has become a high-value LFP resource recovery technology direction. This article analyzes the preparation process of stripping unsprayed LFP electrode slices to repair LFP cathode materials using different commercially available processes. The repaired LFP cathode materials are tested using ICP, SEM, XRD, carbon sulfur, and coulombic discharge to assess their chemical composition, morphology, phase, particle size distribution, carbon content, compacted density, resistivity, conductivity, first-cycle discharge specific capacity of the half-cell, and initial coulombic efficiency. Comparative analysis shows that the stripping process using a solution method results in lower aluminum content and magnetic impurities in the prepared LFP cathode materials; the low-temperature pyrolysis method yields LFP that can be repaired by lithium supplementation, achieving a discharge specific capacity of 157.92 mAh/g at 0.1 C （2.0~3.75） V and an initial coulombic efficiency of 99.55%, meeting the requirements for low-end energy storage and A00-class car power batteries. Therefore, the process of repairing LFP cathode materials using low-temperature pyrolysis and lithium replenishment is one of the most promising methods for obtaining high-quality repaired LFP cathode materials.