Aluminum nitride ( AlN ) has become a key material in the field of electronic packaging and thermal management due to its excellent thermal conductivity, insulation and thermal expansion coefficient matching with silicon. However, AlN powder is easily hydrolyzed with water or in a humid environment to form aluminum hydroxide (Al(OH)₃) or hydroxyl alumina ( AlOOH ), resulting in the loss of nitrogen content and the increase of oxygen content, which reduces the thermal conductivity of subsequent ceramics and thermal interface material, hindering the industrial application. In this paper, the hydrolysis mechanism of AlN powder is systematically reviewed, and the regulation of various factors on the hydrolysis behavior is clarified. The surface modification technology of aluminum nitride powder is reviewed. Finally, the problems existing in the current research are pointed out, and the future development direction is prospected, which provides theoretical support and technical reference for the efficient application of AlN powder in the field of electronic devices.

Al_xCu_1-xCoFeNi high entropy alloys (x=0.25, 0.5, and 0.75) were prepared using a combination of mechanical alloying and spark plasma sintering methods. The phase composition, microstructure, and mechanical properties of the high entropy alloy powder and sintered specimens at different stoichiometric ratios were studied. The results show that the sintered Al_xCu_1-xCoFeNi high entropy alloy with a ball milling time of 64 hours forms a single face centered cubic solid solution when x=0.25 and 0.5, while the high entropy alloy forms a face centered cubic and body centered cubic solid solution structure when x=0.75. At x=0.25, 0.5, and 0.75, the densities of the sintered Al_xCu_1-xCoFeNi high entropy alloy specimens are 98.3%, 95.8%, and 97.7%, respectively. At x=0.25 and 0.5, there is segregation of Al and Cu elements in the Al_xCu_1-xCoFeNi high entropy alloy, while at x=0.75, there is segregation of Al elements and no obvious segregation of Cu elements in the high entropy alloy. As the value of x increases from 0.25 to 0.75, the yield strength, fracture strength, and hardness of Al_xCu_1-xCoFeNi high entropy alloy gradually increase, while the compressive strain gradually decreases. Compared with cast AlCuCoFeNi high entropy alloy, the yield strength, fracture strength, compressive strain, and hardness of high entropy alloy are higher at x=0.25.

As an economic technology with the advantages of powder metallurgy and precision hot die forging, powder forging is a near-net-shape manufacturing technology, which produces parts with high precision and excellent mechanical properties by forging the preformed sintered compact. In this study, we provide a strategy to study the powder forging process as well as the mechanical properties of aluminum alloys using 6061 as an example. The constitutive equations and thermal processing maps of the sintered 6061 aluminum alloy are established through the thermal simulation, and on the basis of thermal analyses, the 6061 aluminum alloy is fabricated via powder metallurgy followed by precision hot die forging. Investigation on the microstructure and mechanical properties of as-sintered and as-forged aluminum alloys before and after T6 heat treatment are also carried out. The results show that the sintered 6061 aluminum alloy without instability during deformation in the range of 425-500 ℃/0.01-1 s^-1, indicating its excellent hot workability. Compared with the as-sintered alloys, the average grain size of as-forged alloys decreased from 12.3 μm to 9.6 μm, which enabled a uniform distribution of alloying elements. As a result, the density, hardness, yield strength and tensile strength reach 99.71%, HV64.7, 129 MPa and 220 MPa, respectively. In particular, it is noted that the as-forged alloy experienced a 138% increase in its elongation, achieving 29.6%. After T6 heat treatment, the as-forged alloys exhibit a hardness of HV135.2, a yield strength of 301 MPa, a tensile strength of 308 MPa and an elongation of 12%, and the dominant strengthening phases are composed of β" and β phases.

In order to investigate the effect of laser power on the organization and properties of iron-based alloys, iron-based alloy coatings were prepared on the surface of 45 steel using laser cladding technology, and the specimens were analytically characterized through microstructure observation, hardness experiments, and electrochemical tests to study the effect of different laser powers (1 100, 1 400, 1 700, and 2 000 W) on the organization and properties of iron-based alloy coatings. The results show that the coatings prepared with different laser powers have no defects such as porosity and cracks, and are well combined with the substrate. The phase composition of the coating mainly consists of α-Fe, γ-(Fe,Ni), α-(Fe-Cr), and γ-(Ni-Cr-Fe) phases. With the increase of laser power, the dilution rate of the coating increases, the equiaxed grains also increase gradually, and the hardness tends to increase first and then decrease. When the laser power is 1 400 W, the coating hardness is 565.4 HV0.2 at maximum, E_corr is -0.339 V at maximum, i_corr is 3.19×10^-6 A·cm^-2 at minimum, and R_ct is 71.8 kΩ at maximum, with the best corrosion resistance.

The combustible metal aluminum powder which is generated at the production and processing process in the industrial and trade industry has a greater risk of explosion. Building a combustion and explosion characteristics system of aluminum powder will help provide the key data support for the prevention and control of aluminum dust explosions. This review systematically discussed the experimental methods and results of aluminum powder flame speed, flame temperature, ignition sensitivity, and maximum explosion pressure, and then provided the commonalities and differences in the conclusions of aluminum powder combustion and explosion research and explored different experiments factors affecting the results. Finally, the evolution rules of the combustion and explosion characteristics of aluminum powder under different influencing factors were discussed.

With the rapid development of new energy vehicles, communications, and other technologies, there is an increasing demand for high-performance pure copper radiators with complex structures. Traditional forging, casting, powder metallurgy pressing and other processes are difficult to manufacture complex structure products, while machining, 3D printing and other processes are more costly, not easy to promote on a large scale, the metal powder injection molding process has the advantage of low-cost, batch manufacturing of complex shaped products, and is expected to realize the complex structure of the scale manufacturing of pure copper radiator. At present, the pure copper powder injection molding process faces technical challenges such as high cost of spherical powder and low sintered density. Therefore, this paper systematically summarized the research progress of pure copper powder injection molding process, focused on the research status of key processes such as feedstock preparation, injection molding, debinding and sintering, and put forward suggestions for future development, in order to provide references for advancing the engineering application of pure copper injection molding process.

The energy density of traction Li-ion battery is its most important performance index. The metal lithium anode possesses ultra-high theoretical capacity (3 860 mAh/g) and ultra-low reduction potential (-3.04 V H⁺/H), and the energy density of the battery can be greatly improved by replacing the graphite anode. However, the biggest problem metal lithium anode suffer from is the electrochemical instability with the electrolyte, which result in intensified side reactions, the consumption electrolyte and the increasing the capacity decay. In addition, the growth of lithium dendrites caused by side reactions at the interface also increases the safety hazard and restricts the development of lithium metal batteries. To solve the as mentioned problems, in this study, magnetron sputtering method is used to deposit lithium phosphate (Li₃PO₄) as an artificial solid electrolyte interphase on the surface of lithium metal anode, so as to obtain high electrochemical stability of the lithium metal/electrolyte interface, and effectively inhibits the polarization of the battery. At the same time, the growth of lithium dendrites is also inhibited due to the increased lithium plating and stripping uniformity. With the modification of Li₃PO₄, which is ionic conductive and electron blocking, the time-constant mode critical circuit density increases from 1.6 mA/cm² to 3.6 mA/cm², and the capacity-constant mode critical circuit density increases from 4.0 mA/cm² to 8.6 mA/cm². The assembled pouch battery achieves an energy density of 355 Wh/kg and a capacity retention rate of 90.8% after 150 cycles at 0.2 C.

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.

The powder of GH4698 superalloy was prepared by supreme speed plasma rotating electrode processing (SS-PREP), and a test billet was sintered by hot isostatic pressing (HIP). After the standard heat treatment, the microstructure and tensile properties of the powder metallurgy GH4698 was investigation. In this work, the mechanical properties of GH4698 superalloy prepared by SS-PREP+HIP+heat treatment route can meet the requirements of forgings. The average tensile strength at room temperature and 750 °C is 1 325 MPa and 873 MPa, respectively, which is better than cast wrought+heat treatment process. The average elongation at room temperature and 750 ℃ are 26.7% and 6.6%, respectively, which is slightly lower than that of cast wrought + heat treatment process. The average impact energy and toughness at room temperature are 60.1 J and 75.3 J/cm², respectively.

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.

A technology to modify the surface of the substrate with alumina powder particles was proposed, and the alumina particles with a diameter of tens of microns were successfully embedded into the metal surface layer of 5052 aluminum alloy at high speed and accurately by using a laser oscillator combined with a sandblasting device. The laser-induced powder jet technology uses a laser to melt the surface layer of the substrate only , and then uses high-speed jetting of alumina particles to quickly embed in the molten layer of the aluminum alloy substrate to enhance the surface properties of the material. The cross-section of the sample was observed by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX), and the depth of the embedded particles could reach about 100 μm, and the number and distribution range of the embedded alumina particles were detected. The effects of key process parameters such as jet pressure, laser energy flow density (the flow rate of laser energy per unit area) and particle incidence angle on the embedding depth, embedding amount and particle percentage were further discussed, which provided a theoretical basis and experimental data support for optimizing the process conditions of this technology. The successful development of this technology not only expands a new way of surface modification of materials, but also provides a new technical solution for improving the wear resistance and corrosion resistance of metal materials.

Cu-12.5Ni-5Sn alloy was prepared using spark plasma sintering (SPS). The effects of sintering temperature, sintering pressure and holding time on the densification and mechanical properties of the alloy were investigated. The optimal SPS conditions as well as the relationship between microstructure and mechanical properties of the alloy were explored. The results show that the densification, hardness and yield strength of alloy all show a trend of first increasing and then decreasing with the increase of sintering temperature, sintering pressure and holding time. When the sintering temperature is about at 870 ℃, the sintering pressure is about 25 MPa, and the holding time is about 30 min, the densification of the alloy is above 98%, and the hardness and yield strength of the alloy after aging treatment reach the maximum values of 252HB and 468 MPa, respectively. Aging treatment can promote further refinement and formation of the lamellar structures in alloy. The γ-CuNi₂Sn phases enriched with Ni and Sn with different shapes are formed at grain boundaries and within grains after aging treatment. In addition, the lamellar γ-CuNi₂Sn phases are identified as discontinuous precipitated γ-DO₃ phases, which are alternately arranged with the spinodal structures to form sandwich structures. The spinodal decomposition strengthening and precipitation strengthening are the main reasons for the good mechanical properties of the alloy.

In order to provide systematic theoretical support for the optimisation of the preparation process of metal-bonded diamond tools, the effects of different metals on the properties of diamond under hot pressing conditions were experimentally investigated. The metal bond prepared in the hot pressing and sintering process was corroded by the acid corrosion method, and the diamond obtained after corrosion was compared and analysed with the original diamond in terms of surface morphology, surface corrosion rate, corrosion depth, etc., and the diamond was tested for compressive strength. The results show that with the increase of temperature, the surface corrosion rate of diamond rises and the surface corrosion depth gradually increases, which leads to a significant decrease in the compressive strength of diamond. Under the same hot pressing conditions, after the hot pressing sintering of Fe, Co, Ni, Cu, Cr and Ti, the surface morphology and properties of diamond show different degrees of changes. Specifically, under the hot pressing and sintering condition at 700 ℃, Ti has the least effect on the compressive strength of diamond, and the corrosion rate and depth of diamond are 66.7% and 0.453 μm, respectively, compared with Cr and Fe, which have a significant decrease in the compressive strength of diamond, and the corrosion depth of diamond is higher than the corrosion results of the other metals. Raman analyses reveal that the surface structure and properties of diamond do not change significantly in most cases, and only a few graphite structures appear after Fe and Co corrosion.

To study on the influence of powder preparation processe on NiCrAlY powders and coatings.Atmospheric Plasma Spraying (APS) were prepared using Ni-Cr-Al-Y alloy powders fabricated by the close-coupled gas atomization and the ultrasonic gas atomization. The physical properties,morphology, elemental distribution,internal microstructure and phase composition of the NiCrAlY alloy powders and coatings were compared. The results show that the two powders have the similar chemical composition and physical properties,with both exhibiting a near-spherical particles shape,but differing in particle size composition.Their microstructures are both composed of dendrites and cell-like structure. The yield and the solidification cooling rate of close-coupled atomization powder with the particle size of 45-90 μm are 30.69% and 1.25-2.49×10⁴ k/s. In contrast, the yields and the solidification cooling rate of ultrasonic gas atomization powder with the particle size of 45-90 μm are exceed 60% and 1.18-2.08×10⁴ k/s, and the distribution of the dendrities and cellar crystals is more regular.Two APS coating have a typical layered structure. The coating fabricated by the close-coupled gas atomization powder has a porosity rate of 12.81% and a bonding strength of 36.8 MPa. In comparison, the coating fabricated by the ultrasonic gas atomization powder has a porosity rate of 11.35% and a bonding strength of 34.8 MPa. Close-coupled gas atomized and ultrasonic gas atomized powders differ in particle size distribution and phase structure. The coatings prepared from the two atomized powders have similar cross-sectional morphology, element distribution, and coating properties. For the close-coupled gas atomized powder contains more fine particles and has a complex phase structure, which leads to significant changes in the element content of the coating, along with poor crystallinity, high porosity, and high microhardness.

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】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.

Based on the reduction reaction and thermodynamic model, a systematic analysis was conducted on the thermal energy consumption and structural composition of the two-stage reduction process of molybdenum powder using a horizontal four-tube furnace as the reduction equipment. The results show that the heat consumed in the reaction process accounts for 17.87%, while the heat carried away by the excess reaction gas accounts for 68.54%. From the perspective of energy consumption management, energy consumption management strategies for the two-stage reduction process of molybdenum powder were proposed from three aspects: thermal efficiency improvement, heat loss control, and thermal effect assurance. Firstly, the thermal efficiency is improved through precise regulation of the hydrogen atmosphere in the reduction furnace; secondly, heat loss is reduced by combining equipment inspection with waste heat recovery and utilization; thirdly, the thermal effect is ensured by optimizing the equipment temperature control and data monitoring system. These multiple measures provide directions for equipment transformation and process optimization.

High-nitrogen steel samples were prepared by adding chromium nitride into the powder and using laser selective zone melting technology at atmospheric pressure, and the effects of different laser parameters on the organization, physical phase and mechanical properties of high-nitrogen steel were systematically investigated. The experimental results show that when the laser energy density increases, the defects of the samples show a trend of increasing and then decreasing. When the laser energy density is too high, it will aggravate the overflow of nitrogen in the powder to form more defects. The physical phase of the sample is dominated by austenite and ferrite, martensite and the austenite phase content of the sample decreases with the increase of laser energy density. The samples with chromium nitride added have a yield strength of 822-1 057 MPa at 1 134-1 254 MPa and an elongation of 9.6%-16.64%. The fracture behavior of the samples is mainly dominated by ductile fracture, and some regions are brittle fracture. The fracture behavior of the samples was mainly characterized by ductile fracture when the energy density was 130.21 J/mm³ (laser power 250W, scanning speed 800 mm/s, scanning spacing 0.08 mm, powder thickness 0.03mm), the overmatching powder laser selective zone melting and forming specimens showed the best mechanical properties.

As one of the important technologies in powder metallurgy, hot-isostati-pressing near-net-shape (HIP-NNS) technology has been widely used in the aerospace field in recent years, it has ability to prepare high-performance products with complex structures. Due to their excellent mechanical properties and corrosion resistance, duplex stainless steel (DSS) products have attracted attention from marine engineering, shipbuilding, nuclear power, petrochemical and other industries. HIP-NNS technology, Shima plastic deformation model and MSC. Marc finite element software were used in the paper. The densification of DSS powder simulation and the prediction of deformation size were completed, and the changes in powder relative density and equivalent stress were analyzed .The results show that the numerical model achieves high prediction accuracy, with a maximum size error of no more than 3%. The numerical simulation method is used to accurately predict the deformation of the package and the powder densification process, greatly improving powder utilization and production efficiency, reducing processing costs, and providing a innovative approach for achieving integrated forming of complex DSS products.

The nine-claw synchronizer cone ring is a critical component used in the lock-pin synchronizers of heavy-duty truck transmissions with high torque requirements. This study investigates the manufacturing process of the nine-claw synchronizer cone ring using powder metallurgy (PM) technology as an alternative to traditional casting and forged steel methods. The selected material is a diffusion-alloyed powder blend of Fe-0.5Mo-4.0Ni-1.5Cu-0.8C, and the manufacturing process includes powder compaction, sintering with copper infiltration, precision machining, and heat treatment. The resulting PM nine-claw cone ring achieves a density of 7.49 g/cm³, a surface hardness of HRC 31, and a tensile strength of 623 MPa, meeting all performance requirements for transmission assembly and service life in heavy-duty trucks. The powder metallurgy process overcomes the drawbacks of the original 40Cr cast steel cone ring, including excessive weight, high machining demands, complex procedures, low production efficiency, and high costs. This method offers advantages such as reduced machining, energy and material savings, high efficiency, and low cost, making it suitable for mass production.

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.

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.

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.

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.

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.

Through the combination of numerical simulation and experiment, the interaction mechanism between gas and liquid in the atomization process of Ni60A superalloy was studied, and the volume of fluid (VOF) multiphase flow model and DPM (discrete phase model) method were adopted. The influence of atomization pressure on the crushing process and particle size distribution of KHRT (kelvin-helmholtz rayleigh-transport) model during primary and secondary atomization of high-temperature melt was studied, and the results were compared with the experimental results. The results show that with the increase of atomization pressure, the return area increases gradually, and the particle size decreases first and then increases. When the atomization pressure is 2 MPa, the error between the particle size prepared by the experiment and the numerical simulation results is 4.8%, which verifies the accuracy of the numerical simulation of Ni60A alloy powder atomization crushing process.

AlCoCrFeNi high-entropy alloy (HEA) particles were selected as the reinforcing phase to prepare HEA/Al composite materials using Friction Stir Processing (FSP) and Submerged Friction Stir Processing (SFSP) techniques. The properties of composite materials were analyzed using XRD, scanning electron microscopy, microhardness tester, and tensile testing machine. The experimental results show that both FSP and SFSP successfully prepared composite materials with high-entropy alloy particles uniformly distributed in the 5083 aluminum alloy matrix. Compared with FSP process, the HEA/Al composite material prepared by SFSP process has a more uniform and dense distribution of high entropy alloy particles, a smaller interface reaction layer thickness （about 150~200 nm）, no obvious reaction products generated at the interface, and a finer grain structure. Compared with the composite materials prepared by FSP process, the composite materials prepared by SFSP have better strength and plasticity, and the fracture surface has ductile fracture characteristics without obvious particle pull-out features. Compared to the 5083 Al matrix, the hardness of SFSFed HEA/Al composite material increases by 69.6% and the wear rate decreases by 48.2%.

The characteristics of single-pass and single-layer cold-sprayed pure Cu coatings have not been extensively studied. In this research, cold spray technology was employed to deposit single-pass and single-layer pure Cu coatings onto 6061 T6 Al alloy plates under varying gas temperatures and pressures. The surface roughness of the coatings was measured using a three-dimensional profilometer, while the thickness, microstructure, and phase composition were analyzed using OM, SEM, and XRD techniques, respectively. SEM images, in conjunction with Image Pro software, were used to calculate the porosity of the coatings. Additionally, the microhardness and shear strength of the coatings were evaluated using a micro Vickers hardness tester and a universal mechanical testing machine, respectively. The shear fracture morphology of the coatings was observed using SEM. The results indicate that an increase in gas temperature results in higher coating thickness and shear strength, accompanied by a gradual decrease in surface roughness, porosity, and microhardness. Conversely, increasing gas pressure lead to corresponding increases in surface roughness, microhardness, and shear strength, while reducing porosity. Ultimately, the study elucidates the relationship between the microstructure and mechanical properties of single-pass and single-layer pure Cu coatings and spraying parameters, laying a foundation for further research on high-performance pure Cu coatings.

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.

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.

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.

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.

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.

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.

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.

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.

Due to the brittleness, high hardness, and stable chemical properties of single crystal sapphire, there are challenges in the cutting process such as low processing efficiency, short lifespan, internal cracks, and surface scratches in the extracted crystal rod. Therefore, it is crucial to urgently address the need for an efficient and high-quality cutting process for sapphire. On diamond drill head formulation, a constrained formulation design method was adopted. The impact of different components on bit sharpness and lifespan was discussed. To evaluate these improvements, regression analysis was conducted by using SPSS to explore the relationship between the components. The identification of primary and secondary relationships between performance indices and each component along with statistical significance assessment was conducted through t-test analysis. Finally, an optimal matrix ratio scheme was obtained by using Excel solution. Experimental results demonstrate that the constructed Scheffe regression equation accurately predicts experimental outcomes. F-tests and t-tests on formula design test data reveal that WCu powder content has a significant influence on sapphire drill sharpness, with optimum sharpness achieved at 35wt% WCu powder while FCS20 is at 30wt% and Co powder is at 35wt%. This also leads to improved surface quality of the sapphire crystal rod. The constrained uniform formulation design significantly reduces testing efforts while obtaining optimal results.

【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.