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.

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.

In high-voltage power transmission systems, W-Cu electrical contact alloys are subjected to complex environments involving high-temperature arc ablation, SF6 gas erosion, and mechanical wear, necessitating a combination of high conductivity, strength-toughness, and corrosion resistance. This paper systematically reviews the microstructure regulation mechanisms of preparation technologies such as electroless plating, melt infiltration, spark plasma sintering (SPS), mechanical alloying, and microwave sintering, and discusses the influence of different processes on the interfacial bonding characteristics of W/Cu. The study comprehensively analyzes The effects of metal particles, ceramic phases, and fiber reinforcements in enhancing arc erosion resistance through mechanisms such as grain refinement strengthening and second-phase strengthening, while summarizing the synergistic regulation mechanisms of reinforcement phase morphology distribution and interfacial reactions on the material's overall performance. Current research demonstrates that multicomponent composite reinforcement systems effectively mitigate the conductivity-mechanical property trade-off. For instance, microwave-sintered materials with nano dual-phase reinforcement maintain high electrical conductivity even under significant hardness improvement. Future efforts should focus on developing core-shell structured nano-reinforcements, external field-assisted sintering technologies, machine learning design platforms, and full-lifecycle performance evaluation systems to address the challenge of conductivity-strength synergy. With the integration of multidisciplinary approaches, W-Cu alloys are expected to deliver next-generation high-performance contact material solutions for smart grids and extreme-environment electrical devices.

Binder jet 3D printing (BJ3DP) is a non-melting, high-efficiency, and cost-effective metal additive manufacturing technology. In recent years, it has shown great potential in producing complex structures, large-sized parts, and high-precision components. Compared with laser melting techniques, BJ3DP offers several advantages, such as broad material compatibility, low processing temperature, and the absence of residual stress. These features make it particularly suitable for heat-sensitive or easily oxidized metals. This paper reviews the key factors affecting the quality of metal parts produced by BJ3DP, including powder characteristics, printing parameters, and debinding/sintering processes. It focuses on the phase evolution, microstructure, and mechanical properties of various alloy systems, such as iron-based, nickel-based, magnesium-based, aluminum-based, and high-entropy alloys, etc. Finally, current challenges and future development trends were briefly outlined.

Because of its high hardness, high strength, good plasticity and excellent heat shock resistance and creep resistance, rhenium metal has been widely used in aerospace nuclear industry, catalysis field, electronics field, biomedicine and other high-tech fields. In this paper, the preparation methods of rhenium powder and rhenium products are reviewed, among which the hydrogen reduction method is the most popular. The preparation of rhenium powder is developing in the direction of increasing the purity of rhenium powder. The mature preparation methods of rhenium products include powder metallurgy, electron beam melting and chemical vapor deposition. The production cost of powder metallurgy is low, but the production of complex components is difficult. The purity of the product prepared by electron beam melting is high, but the cost is high and the production of complex components is difficult. Chemical vapor deposition method has high purity and can prepare complex components. It is often used for the preparation of thin film materials, but the cost is high. The three methods are relatively mature, and all have certain industrial production capacity. On this basis, the mechanical properties and creep properties of rhenium prepared by different methods are compared. It is concluded that rhenium prepared by hot isostatic pressing and chemical vapor deposition has better properties. However, hot isostatic pressing method has not been industrialized because of its high cost. Domestic research institutions also need to further explore advanced preparation technology, in-depth study of rhenium deformation mechanism, and explore new application fields.

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.

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.

Magnesium matrix composites are widely used in various industries and have been studied in depth because of their excellent comprehensive properties, such as low density, high specific strength and high specific modulus. This paper mainly reviews the reinforcement mechanism and research progress of SiC on magnesium matrix composites, and finds that SiC can effectively balance the contradictory relationship between strength and plasticity in traditional magnesium matrix composites, and play a good reinforcing effect on magnesium matrix composites. Through the review and analysis, SiC on magnesium matrix composites reinforcement mainly has Orawan strengthening, fine grain strengthening, thermal mismatch strengthening and load transfer strengthening. Meanwhile, the size and distribution of reinforcing particles play a decisive role in strengthening magnesium alloys and determine the strengthening mechanism. For most magnesium alloys, an optimal effect is achieved when the addition of particulate reinforcement is 1 wt%. SiC particles at micro- and nano-scales are more effective in enhancing the mechanical properties of magnesium matrix composites. To achieve high-performance SiC-reinforced magnesium matrix composites, the current optimal methods include melt infiltration, powder metallurgy, stir casting, and high-energy ultrasonic processing. The application of nano-SiC reinforcements in magnesium matrix composites represents a cutting-edge research topic. Through meticulous design and fabrication, it is expected to enhance the mechanical properties, wear resistance, and corrosion resistance of magnesium matrix composites, thus holding broad application prospects in fields such as aerospace, automotive, and electronics.

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.

Additive manufacturing is an emerging material forming technology, whose shaping process is a typical non-equilibrium solidification process, involving complex physical phenomena such as temperature, thermodynamics, and phase transitions. It is difficult to measure and analyze the changes in physical quantities during the additive manufacturing process using traditional methods. Applying finite element numerical simulation technology to additive manufacturing can effectively calculate and predict the processing and outcomes, enhancing the efficiency of research and development in additive manufacturing and reducing costs. This paper provides a comprehensive review from three aspects: the finite element numerical simulation method, the introduction of finite element numerical simulation software, and their current applications in the field of additive manufacturing. It analyzes the advantages and limitations of finite element numerical simulation technology in the additive manufacturing field and offers a perspective on future development trends.

Using metallographic microscope, scanning electron microscope, oxygen-nitrogen analyzer, laser particle size analyzer, and X-ray diffraction analyzer, the characteristics of M50NiL powder prepared by plasma rotating electrode process （PREP), including the microstructure and phase composite, nitrogen-oxygen content, particle size distribution, and flowability were characterized. The results indicate that the powder has a relatively narrow particle size range, primarily distributed between 30-53 μm, with a unimodal distribution and a Gaussian distribution curve. The average particle size is 45.21 μm. The chemical composition of the powder is uniform, with high purity and no other impurities. Metal powder has low nitrogen-oxygen content with the below 0.024% of the oxygen and the below 0.025% of the nitrogen. The M50NiL powder with different particle sizes are primarily composed of α phase. The solidification structure varies with the change of the particle size: 15-53 μm consists of fine cellular and dendritic structures, whereas 53-150 μm is dendritic, and >150 μm is characterized by coarse equiaxed crystal structures. M50NiL powder has excellent physical properties and meets the technical requirements of powder bed fusion additive manufacturing.

The effects of 1% TiB₂ particles as reinforcing phase on the microstructure and properties of Al-Zn-Mg-Cu alloy were studied. Al-6Zn-3Mg-Cu aluminum alloy and TiB₂/Al-6Zn-3Mg-Cu composite material were prepared using Spark Plasma Sintering (SPS) technology. The desired samples were obtained after hot forging, hot extrusion, and T6 heat treatment, followed by the study and analysis of the samples' microstructure and mechanical properties. The results indicate that there is no macroscopic segregation of alloy elements, and TiB₂ particles are uniformly distributed in the aluminum alloy matrix. The grain size of the aluminum-based composite material modified with TiB₂ is refined, the defects and pore aggregation in the structure are reduced, and the TiB₂ promotes the uniform distribution of MgZn₂ precipitation phase in the matrix. Due to the combined effects of grain refinement, improvement of microstructure, age-hardening precipitation of MgZn₂, and reinforcement from TiB₂ particles, the TiB₂/Al-6Zn-3Mg-Cu composite material achieves ultimate tensile strength, yield strength, and elongation of 539 MPa, 495 MPa, and 10.3%, respectively, showing improvements over the Al-6Zn-3Mg-Cu alloy in all three aspects.

The high-temperature alloy GH3536, celebrated for its exceptional thermal stability and oxidation resistance, is of paramount importance in sectors such as aeronautics and astronautics. However, conventional manufacturing techniques are limited to produce complex structural components. Thus, laser powder bed fushion (LPBF), an advanced near-net-shape manufacturing process, is increasingly recognized as a vital technology for the rapid fabrication of high-temperature alloy parts with intricate geometries. In this study, LPBF was employed to fabricate GH3536 high-temperature alloy components, and the effects of process parameters on microstructural characteristics and mechanical performance were systematically analyzed. The main phase structure of GH3536 high-temperature alloy formed by LPBF is FCC structure, accompanied by a small amount of M₂₃C₆ phase and martensitic (α) phase, with a multi-level structure of molten pool-large columnar crystals-super cellular crystals. It is also observed that upon increasing energy density, the density initially increased but subsequently decreases. The optimal processing window for GH3536 high-temperature alloy formation is identified as between 104.00 and 120.00 J/mm³, achieving a density in excess of 99.5%. Notably, at an energy density of 104.17 J/mm³, the alloy exhibited fine cellular crystal structures and high density. Under these optimal conditions, the GH3536 high-temperature alloy exhibits an exceptional combination of strength and ductility, achieving a yield strength of 649.45 MPa, a tensile strength of 854.74 MPa, and an elongation of 32.30%.

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.

To address the challenge of low-pressure powder laying while ensuring high packing density, the influence of the two-stage powder spreading spreader on the quality of the powder bed of binder jetting additive manufacturing (BJAM) is investigated. The effects of roller, scraper, and two-stage powder spreaders on the quality of the powder bed and substrate pressure were compared. Additionally, the impact of the pre-spread layer thickness of the two-stage powder spreader on powder spreading was analyzed. The powder dynamics during the spreading process were examined using the discrete element method to validate the experimental results.The findings indicate that, under the same layer thickness and spreading speed, the quality of the powder bed achieved with the two-stage powder spreading is comparable to that of roller powder spreading and superior to scraper powder spreading. However, the average pressure on the bed with two-stage powder spreading is significantly lower, at 427 Pa, compared to 2178 Pa with roller powder spreading. The pre-spreading layer thickness significantly affects the compaction effect of the powder bed. When the pre-spreading layer thickness increases from 150 μm to 250 μm, the packing density of the powder bed shows a notable improvement. However, beyond 250 μm, the density growth tends to saturate, while the substrate pressure continues to rise steadily with further increases in the pre-spreading layer thickness. These findings provide theoretical insights for optimizing powder spreading mechanisms and process parameters in BJAM, offering a viable strategy to enhance manufacturing efficiency and part reliability.

The stress and deformation of overhanging structures in laser powder bed fusion (LPBF) are critical issues for achieving high-quality and high-precision manufacturing of complex metal components. Real-time strain data measurement during the LPBF process of overhanging structures was achieved by embedding strain gauges in the substrate. Based on the in-situ strain measurement system, the strain behavior of T-shaped overhanging structures and low-angle overhangs (5° and 10°) during the LPBF process was investigated. The effects of different cantilever lengths and various process parameters on the in-situ strain behavior of T-shaped overhangs were analyzed in detail. Furthermore, the influence of different overhang angles and support types on the in-situ strain behavior of low-angle overhanging structures was analyzed. The results indicate that the longer the overhanging length of the T-shaped structure, the greater the deformation. The use of a laser energy gradient and island scanning strategy effectively reduces the deformation of T-shaped overhanging structures. Additionally, the design of the support structure significantly affects the strain behavior and forming quality of low-angle overhanging structures. The optimal forming quality is achieved using the H1 support design strategy (block support spacing of 0.8 mm and conical support spacing of 0.6 mm). These findings provide valuable insights for understanding and controlling the deformation behavior of overhanging structures in the LPBF process.

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 diamond/Ni-Cu composite specimens which can be used in the carcass of polycrystalline diamond compact (PDC) drills were successfully prepared by using electron beam selective melting (EBSM) technology, and the effects of diamond volume fraction on the density, flexural strength, wear resistance and erosion resistance of diamond/Ni-Cu composites were systematically investigated. The results indicate that with the increase of diamond volume fraction, the density and flexural strength of diamond/Ni-Cu composite samples generally show a trend of first decreasing, then entering a relatively stable stage, and then rapidly decreasing. However, the wear ratio of diamond/Ni-Cu composites specimens shows a trend of increasing first and then rapidly decreasing when the volume fraction of diamond increases from 10% to 35%, and the wear ratio reaches the maximum value of 1.08 when the volume fraction of diamond is 25%. However, the erosion mass loss of the diamond/Ni-Cu composite specimens shows a trend of first decreasing and then increasing as the volume fraction of diamond gradually increases from 10% to 35%. When the weight loss reaches the minimum value of 7.50 mg, the volume fraction of diamond is 25%. Therefore, when the diamond volume fraction is 25%, the wear resistance and erosion resistance of the diamond/Ni-Cu composites prepared by EBSM are optimized simultaneously.

To investigate the influencing factors of crack formation and the wear mechanism of Fe₃Al/Cr₃C₂ composites, orthogonal experiments were conducted by laser cladding Fe₃Al/Cr₃C₂ composite coatings on carbon structural steel substrates. The coatings were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and wear tests. The results show that among the factors affecting crack formation in the cladding layer, the Cr₃C₂ content is the most critical. Coatings with 15% and 25% Cr₃C₂ exhibit the fewest cracks. In terms of wear resistance, these same coatings also display the lowest wear rates, which can be attributed to their reduced tendency for adhesive wear and the refined microstructure of the reinforcing phases that facilitate surface separation during abrasion. The morphology and distribution of the reinforcing phases in the cladding layer play a crucial role in wear resistance. During friction, the softer Fe₃Al matrix wears away first, while the harder carbides support the worn surface and reduce friction. As wear progresses, the carbides gradually disappear from the surface and transform into hard phase particles.

The gas flow field of electrode-induced melting gas atomization technology was simulated using the FLUENT software for fluid dynamics. The influence of supersonic nozzle on different inlet pressures (2, 3, 4 MPa), angles (40°, 45°, 50°), and distances (12, 18, 22 mm) between the supersonic nozzle outlet and metal flow were analyzed. The results indicate that the gas flow field exhibits a series of expansion wave and compression wave jet structures. Increasing the injection pressure effectively enhances the velocity of the gas jet and theoretically generates greater shear force to facilitate atomization. Proper adjustment of the nozzle angle minimizes pressure loss between the gas and pipe wall while controlling the position of the return gas field. Additionally, the distance between nozzle outlet and metal liquid flow affects the location of reflux gas field. As this distance increases, there is a gradual reduction in speed as well as convergence into reflux gas field before being far away from nozzle outlet. If reflux gas field is near center hole (liquid flow down channel) of nozzle, it hinders downward liquid flow leading to reverse injection and splashing. Conversely, if return gas field is far from center hole of nozzle, insufficient atomization occurs resulting in coarse powder particles with irregular shapes.

Laser powder bed fusion (LPBF) additive manufacturing has made significant progress in fabricating multi-material metallic structures, where the quality of the heterogeneous powder bed is a critical factor affecting the final part quality. Among these factors, interparticle cohesion plays a pivotal role in the powder spreading process. Taking 316L stainless steel and CuSn10 alloy as examples, the discrete element method is used to numerically simulate the spreading process of multi-material powder beds, so as to evaluate the influence of interparticle cohesion on the quality of powder layers. Additionally, the impact of cohesion on the formation of sharp interfacial boundaries along the powder spreading direction was examined. Key findings include: (1) Increased interparticle cohesion worsens powder spreadability and exacerbates particle size segregation. (2) Cohesion induces powder agglomeration, leading to cross-contamination. (3) Higher cohesion reduces powder flowability, increases the angle of repose, and results in poor boundary quality with steep gradients.

WE43 magnesium alloys exhibit significant potential for applications in aerospace, biomedical, and transportation fields. Laser powder bed fusion (LPBF) technology offers a novel approach to optimize their properties. However, the mechanical performance of magnesium alloys produced via this method is often limited by the anisotropy of their microstructure.In this study, the effects of different deposition orientations on the microstructural evolution and mechanical properties of LPBF-fabricated WE43 magnesium alloys were systematically investigated. The results indicate that the anisotropy in mechanical behavior is closely related to the deposition direction. Specifically, the vertically deposited specimens exhibit an average grain size of 1.86 μm, contributing to a fine-grain strengthening effect. In addition, the high density of low-angle grain boundaries hinders dislocation motion, further enhancing mechanical strength. Moreover, under tensile loading along the build direction, the orientation of existing cracks becomes parallel to the applied stress, thereby reducing crack propagation and improving tensile performance.As a result, vertically deposited specimens demonstrate superior tensile properties compared to the horizontally deposited counterparts, with a yield strength of 282 MPa, an ultimate tensile strength of 325 MPa, and an elongation of 12%. This study provides a theoretical basis for optimizing LPBF deposition strategies and lays a technical foundation for the directional design of microstructure and properties in WE43 magnesium alloys.

Laser powder bed fusion (LPBF) processes exhibit highly dynamic, transient, and spatially small-scale characteristics such as keyholes, melt pools, and particle spattering. Conducting in-situ high-speed imaging of powder melting processes aids in deepening our understanding of melt pool dynamics and defect formation mechanisms. This study developed an in-situ imaging system for LPBF using a high-resolution open micro-focus X-ray tube. Observational research focused on phenomena including keyholes, bubble, spattering, and balling during the melting of 316L powder. The results demonstrate the system's capability to detect dynamic changes at the gas/melt pool interface and capture morphological changes of keyholes under certain laser process parameters, including the formation process of keyhole-induced large-scale porosity (~100 μm). Furthermore, it is found that higher X-ray tube voltages (e.g., 220 kV) enhance the system's ability to discern melt pools, although excessive X-ray penetration at this level prevents imaging of small-sized spatters. Conversely, lower X-ray tube voltages (e.g., 90 kV) effectively capture spattering behavior (~30 μm and above), preliminarily revealing mechanisms such as spatter-induced surface protrusions, significant dimensional deviations, and surface rippling defects in melt tracks. Additionally, dynamic processes of balling are replicated. The development of this technology holds significant implications for advancing in-situ studies of materials and processes in additive manufacturing.

Additive manufacturing enables the fabrication of metallic porous materials that combine the inherent advantages of metals, such as exceptional heat resistance and corrosion resistance, with multifunctional characteristics including high specific surface area and controllable permeability. This study employed laser powder bed fusion (LPBF) to achieve controllable preparation of porous CM247LC nickel-based superalloy through precise modulation of laser power and scanning velocity. The results demonstrate that the LPBF-processed CM247LC alloy primarily consists of γ/γ′ phases, exhibiting an average grain size of 20 μm. Mechanical properties show significant degradation with decreasing relative density. The relative density of 98% superalloy manifests a tensile yield strength of 989.1 MPa and ultimate tensile strength of 1 395.4 MPa, whereas the porous specimen with 60% relative density displays drastically reduced strengths of 132.8 MPa and 223.2 MPa, respectively. Deformation analysis reveals that the dense material undergoes plastic deformation via dislocation slip, evidenced by characteristic river patterns on fracture surfaces. In contrast, the porous structure fails through brittle fracture at sintering necks, highlighting the critical role of porosity in governing failure mechanisms.

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.

Solid metal lithium battery is expected to achieve a high energy density of 500 Wh/kg, which is regarded as the key electrochemical energy storage system to achieve a breakthrough in the driving range for new energy vehicles. However, the poor contact stability between the metal Li anode and the solid electrolyte seriously restricts its cycling performance. In this study, the interfacial stability was modified in the aspect of the volume strain of the interphase between the solid electrolyte and Li anode. Different from the conventional modification strategy with high electrochemical activity interphase, a copper film modified layer with low electrochemical activity between the solid electrolyte and the Li anode is introduced, so that the volume change ratio of the interface phase can be greatly reduced, thus enhancing the stability of the interface contact and improving the cycle stability of the solid lithium metal battery. According to the electrochemical impedance spectroscopy, it is found that the area specific resistance of the anode interface is reduced from 2 030 Ω/cm to 65 Ω/cm by the introduction of copper thin film. The gram capacity of lithium cobalt oxide cathode is increased from 118 to 145 mAh/g. Moreover, the capacity retention of the solid-state lithium battery at 0.33 C after 500 cycles is increased from 46.3% to 93.5%.

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.

The surface of sintered Ti80 alloy was strengthened by surface ultrasonic rolling (USRP) technology, and the microstructure and properties of Ti80 alloy before and after rolling were analyzed by optical microscope (OM) and scanning electron microscope (SEM). The results show that the surface strengthening effect of the sample is the best when the rolling amplitude is 10 μm. The densification effect of the sample after rolling is remarkable. The surface hardness is increased by 18.5% and the surface roughness is reduced by 86%. The tensile strength and yield strength of rolled Ti80 alloy are 992 MPa and 815 MPa, respectively, which are 15.2% and 1.3% higher than those of sintered samples, and the elongation is increased from 1.7% to 2.6%. After soaking in 4 mol/L hydrochloric acid solution for eight days, the weight loss rates of sintered and rolled titanium alloys were 20.6 mg/cm² and 10.6 mg/cm², respectively, and the weight loss rate was reduced by 48.5%, which effectively improved the corrosion resistance of Ti80 alloy.

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.

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.

The process of preparing high nitrogen steel by selective laser melting of high nitrogen stainless steel powder under normal pressure exhibits nitrogen escape, which cannot effectively produce qualified high nitrogen stainless steel. This study prepared 316LN powder by using CrN as a nitrogen enhancer and formed 316LN high nitrogen steel samples using atmospheric pressure selective laser melting method. The influence of process parameters on the formation of high nitrogen stainless steel was investigated. The nitrogen content, nitrogen emissions, phase composition, microstructure, and microhardness of the obtained 316LN high nitrogen steel sample were analyzed using hydrogen oxygen analyzer, X-ray diffraction, and electron back scatter diffraction. The results show that as the laser density increases, the density of the sample showes a trend of first increasing and then decreasing, reaching a maximum value of 95.33% at 138.89 J/mm³. The nitrogen content of the powder decreases with increasing energy density, and the microstructure is mainly composed of small cellular and columnar crystals, with austenite as the main phase. The strength of 316LN powder formed samples shows a certain upward trend with the increase of energy density, while the elongation rate shows a downward trend. Within the range of laser energy density (69.44-182.29 J/mm³), the highest elongation of the 316LN powder formed sample is 21.56%. Overall, when the laser energy density is 130.21 J/mm³ (laser power of 250 W, scanning speed of 800 mm/s, scanning spacing of 0.08 mm, powder thickness of 0.03 mm), the 316LN powder selective laser melting formed sample exhibits excellent mechanical properties.

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.

The evolution mechanism of molten pools and microstructure distribution in the process of preparing 18Ni250 maraging steel by selective laser melting (SLM) technology were explored through simulations and experiments. The research focuses on the molten pools, microstructure evolution and mechanical property testing of SLM-formed parts. Simulation results show that the Marangoni effect occurs when metal powder melts under laser loading, which makes the surface relatively smooth after the molten pool solidifies. Experimental results indicate that the prepared metal bulk has a flat and dense surface. The molten pool sizes obtained from simulation and experiment are quite consistent, suggesting that the prediction of printing quality through simulation is reliable. After heat treatment, the SLM-18Ni250 parts have a tensile strength of 1 970 MPa and a yield strength of 1 900 MPa, which are comparable to those of traditionally forged 18Ni250 maraging steel, but with slightly lower toughness. Observation of the metallographic structure of SLM-18Ni250 reveals that the as-printed molten tracks are regularly distributed, and the microstructure consists of a small amount of austenite and martensite. The solution water quenching treatment transforms austenite into martensite, and after aging and air cooling treatment, the martensite increases significantly with uniform composition, thereby improving the mechanical properties of the material. However, the interlayer bonding and defect distribution of the printed parts result in slightly lower toughness. The research method and idea combining simulation and experiment can provide useful guidance for the preparation of high-strength and high-toughness maraging steel by SLM technology.

Inconel738 powder for laser cladding was prepared using plasma rotating electrode method. Three factor and four level orthogonal experiments were conducted on the powder preparation process, and powder detection, morphology, and microstructure observation were carried out on the obtained process.The results show that the Inconel738 powder prepared by plasma rotating electrode method at a speed of 22 000 r/min, a current intensity of 650 A, and a feed rate of 1.3 mm/s could achieve a powder yield of 91.0%, The powder has a flowability of 10.7 s/50 g and a loose density of 4.78 g/cm³ the oxygen content of 0.68×10^-4,the sphericity of 92%. The powder has good sphericity, smooth surface, almost no hollow powder, and a dendritic structure inside and outside, which can be used for laser cladding.

The microstructure difference of GH4099 alloy formed by laser powder bed fusion and conventional casting was studied. The microstructure evolution of GH4099 alloy formed by the two processes after heat treatment was further analyzed and its effect on mechanical properties was discussed. The results show that the microstructure of GH4099 alloy formed by laser powder bed fusion (LPBF) and cast is epitaxial growth near columnar crystal structure and bimodal equiaxed crystal structure, respectively. The dendritic structure in the grains of the alloys formed by the two processes disappeares, and the carbides and γ' phase precipitate in the subsequent heat treatment, resulting in an increment in ultimate tensile strength and a decrement in plasticity. Compared with cast GH4099 alloy, LPBF GH4099 alloy has static recrystallization and grain refinement after heat treatment, which increases the utimate tensile strength, yield strength and elongation of GH4099 alloy by 66MPa, 187MPa and 14.5% respectively.

This study systematically examines the effects of sintering temperature and desorption treatment on hydrogen content in boron carbide-alumina (WABA) pellets through inert gas fusion-thermal conductivity method. The results demonstrate that elevating the sintering temperature from 1 300 ℃ to 1 590 ℃ reduces hydrogen content by 69.3%. Research on desorption post-treatment shows that the core block exhibits three-stage dehydrogenation characteristics, including pore adsorbed water (<120 ℃, hydrogen content 93.996×10^-6), deep hole condensation water and internal crystallization water (120-550 ℃, hydrogen content 22.211×10^-6), bound hydroxyl groups and residual organic matter (>550 ℃). When RH<30%, the hydrogen content can be reduced to 17.583×10^-6. Helium demonstrates superior dehydrogenation performance compared to argon, achieving 42.2% higher desorption efficiency and enabling hydrogen reduction below 10×10^-6 at RH <30%. Notably, secondary hydrogen absorption occurs when environmental humidity exceeds RH>70%. Process capability analysis confirms stable manufacturing control with CPK values consistently above 2.0 across multiple batches. These findings establish critical theoretical and technical guidelines for hydrogen management in WABA pellets production and quality assurance.

The TiAl alloys were prepared by laser coaxial powder feeding additive manufacturing technology, and the evolution of metallurgical defects in the alloy under different laser powers was thoroughly investigated, and the phase composition, microstructure, and mechanical properties of the alloy were analyzed. The results indicate that as the laser power increases, the melt width and depth of the single melt track in the TiAl alloy gradually grow, and the spheroidization phenomenon diminishes. The alloys demonstrate a high density, with porosity below 0.05%, and the porosity slightly decreases as the laser power increases. When the laser power is 1 200 W, cracks appear near the interface between the formed part and the base material. When the laser power is increased to 1 400 W and 1 600 W, the cracks disappear. The TiAl alloys are mainly composed of the γ phase and a small amount of the α₂ phase. Their microscopic structure feature is that a small number of blocky γ grains are distributed at the boundaries of the γ/α₂ lamellar colonies. With the increase of the laser power, the size of the lamellar colonies of the TiAl alloys shows a gradually increasing trend. When the laser power is 1 400 W, the tensile strength of the TiAl alloy is 476 MPa, and the tensile fracture morphology exhibits the characteristics of brittle fracture.

The relationship between process parameters and microstructure evolution during the deposition process of typical Ni₃Al-based alloy IC-221M prepared by laser directed energy deposition was analyzed, and the mechanical properties at room temperature were obtained. The results of scanning electron microscopy show that the microstructure of the alloy is mainly composed of γ-Ni₅Zr eutectic and γ + γ ' low melting point eutectic phase, as well as the spherical γ ' phase at the dendrite. As the scanning speed increases, the (200) diffraction peak shifts to a low angle, the interplanar spacing and lattice constant gradually increase, and the grain size in the solidified structure gradually decreases. In terms of mechanical properties at room temperature, when the laser scanning speed is 700 mm/min and 800 mm/min, the mechanical properties of IC-221M alloy samples are higher than those of as-cast alloys, the yield strength is higher than 550 MPa, the tensile strength is higher than 750 MPa, and the fracture elongation is more than 13%.

Using an improved powder method combined with a multi-pass bundle drawing technique, a Bi2223/Ag superconducting tape was prepared. Metallographic inspection showes that the deformation of Bi2223 powder core wires in the final superconducting tape is uniform, and the proportions of silver to superconducting area in the tape are stable and uniform. A multi-layer tape stacked superconducting cable conductor is designed and stability simulations of the superconducting cable conductor under complex electromagnetic conditions in magnetic confinement fusion magnets are conducted using THEA code. This involves calculating and analyzing the conductor's current sharing temperature （T_cs） at 4.2 K under different current and background magnetic fields. It also simulates the impact of energy shocks （200~300 mJ/cm³） during plasma disruption events （20~30 ms） on conductor stability. Simulation results demonstrates that the superconducting conductor designed has good stability. Under the impact of energy higher than that of plasma disruption, the local temperature rises quickly and reaches a peak in a very short time and then rapidly returns to the initial temperature. The maximum temperature is lower than T_cs.

Laser powder bed fusion (LPBF) offers a novel pathway for enhancing the performance of lightweight steels through its superior forming capability and microstructure refinement potential. However, current research lacks systematic investigation on LPBF processing of Fe-Mn-Al-Ni-C lightweight steels with high Ni content, while the evolution mechanism of B2 phase and its influence on mechanical properties remain unclear. This study investigates Fe-30Mn-11Al-12Ni-1C lightweight steel through comparative analysis of as-built and heat-treated specimens, focusing on matrix microstructure evolution, B2 phase morphology, dimensional characteristics, and spatial distribution. A defect-free sample with 99.2% relative density was successfully fabricated under optimized parameters (laser power at 95 W, scanning speed at 800 mm/s), followed by microstructure regulation through 1 100 ℃ and 1 200 ℃ heat treatments. The results reveal that the as-printed steel predominantly consists of FCC-γ austenite phase, with angular polygonal B2 particles (average size at 68 nm) discontinuously distributed along grain boundaries, occupying 12.43% area fraction. After 1 100 °C treatment, B2 phase transforms into short rod-like morphology (average length at 0.93 μm) with homogeneous intra- and intergranular distribution, significantly increasing its area fraction to 52.14%. The 1 200 °C treatment induces banded B2 phase formation (average length at 1.89 μm), reducing area fraction to 41.03%. Mechanical characterization demonstrates that 1 100 °C-treated specimens exhibit enhanced microhardness (468.5HV0.2), yield strength (930.2 MPa), and ultimate tensile strength (1 012.6 MPa), but suffer from severe ductility reduction (elongation at 0.88%). The study elucidates that increased B2 phase content and coarsening strengthen materials via secondary phase strengthening mechanism, while their inherent brittleness critically deteriorates matrix plasticity.