Sintered metal porous materials are a special type of metal material that integrates structure and function. They are widely used in industries such as coal chemical, petrochemical, aerospace, new energy, semiconductor, smelting, and environmental protection, and play an important role in the development of the national economy This paper introduces the types of sintered metal porous materials and elaborates on their applications in filtration and separation, fluid distribution control, catalytic loading, and enhanced mass and heat transfer. It predicts the development trend of sintered metal porous materials, which will continue to develop towards material composite, pore size refinement, structural gradient, widespread application, and multifunctionality in the future.

TWIP steel controls stacking-fault energy to create twinned crystal organizations, enhancing ductility and strength. Although extensive research has been conducted on TWIP steels fabricated by melting, limited attention has been given to TWIP steels prepared through powder metallurgy. Furthermore, the current powder metallurgy TWIP steel samples have not fully realized their vast application potential. The materials were prepared at different temperatures and times using a combination of gas-atomized Fe-21Mn-0.7C alloy powder and fast hot pressing technology. The effects of sintering temperature and sintering time on the tissue evolution and mechanical properties of the materials and subsequent hot rolling and heat treatment to further optimize the comprehensive mechanical properties were investigated. The results show that the temperature increases, the holding time increases, the small particle size range powders are fully fused together to form a denser structure, and the grain boundary oxides have basically been depinned. At 930 °C, 40 MPa, and 12 minutes, the alloy achieves a density of 98.86%, tensile strength of 955 MPa, and extensibility of 32.8%. After hot rolling, the tensile strength can reach 1 690 MPa. After annealing, a high-strength and high-toughness steel with excellent comprehensive mechanical properties is obtained, with the tensile strength and elongation being 998 MPa and 46.2% respectively. The annealed material exhibited excellent comprehensive mechanical properties.

In order to predict the shrinkage and deformation during the sintering process of metal green parts fabricated by binder jetting additive manufacturing (BJAM), a high-temperature creep model based on viscoelastic calculation was established to simulate the thermally induced creep behavior during the sintering process. This model establishes a connection between the microscopic and macroscopic descriptions of sintering, taking into account the effects of grain boundary diffusion, the action of gravity, grain growth, and thermal expansion on the sintering shrinkage and deformation. The parameters in the model depend on the particle size, relative density, and temperature. The numerical simulation was implemented by writing a user-defined subroutine CREEP in Abaqus, and the 316L powder widely used in industry was selected for experimental verification. The results show that the average linear shrinkage rates in the x and y directions are 11.61%, while the average linear shrinkage rate in the z direction is 12.64%. Compared with the experimental values (the average linear shrinkage rate in the x direction is 10.12%, the average linear shrinkage rate in the y direction is 10.15%, and the average linear shrinkage rate in the z direction is 11.21%), the error range is approximately 1% to 2%. This indicates that the model has a good predictive effect, especially for 316L stainless steel parts in which grain boundary diffusion is the main sintering mechanism. Optimizing and obtaining more accurate material property parameters, especially under high-temperature conditions, will help to further improve the prediction accuracy of the model.

Laser powder bed fusion (LPBF) exhibits significant advantages in the manufacturing of high-entropy alloys (HEAs) with complex shapes and good strength-toughness properties. To further enhance the mechanical strength of HEAs, adding Nb element is an effective way which could enhance the solid solution strengthening and second phase strengthening effects. However, the structure features of second phase formed during LPBF is prone to brittle fracture, resulting in the significant decrease in the toughness properties of HEAs. Therefore, it is of great significance to study the effect of heat treatment post-processing on the microstructure and properties of HEAs fabricated by LPBF. The CoCrFeMnNiNb_0.15 HEAs were successfully prepared by LPBF first, and then the evolution of phase structure, mechanical properties and fracture morphology were studied after heat treatment. The results show that the heat treatment prompts the structure transformation of Nb-rich Laves phase from the continuous network to the fine and dispersively-distributed particles, and partial Nb element precipitates from the matrix structure of the FCC phase. Besides, the matrix grains also grow up along the (111) crystal orientation. With the increase of heat treatment temperature, the Laves phase and the matrix structure become coarsened gradually. Due to the weakened solid solution strengthening, grain boundary strengthening and second phase strengthening effects after heat treatment, the plastic deformation capability of the FCC phase is improved, thus resulting in the failure mode changed from brittle fracture to ductile fracture. When the heat treatment temperature is 980 ℃, the CoCrFeMnNiNb_0.15 HEAs can obtain the well-matched strength-toughness properties, which shows the product of strength and elongation of 13.2 GPa%, ultimate tensile strength of (892 ± 13.4) MPa, and elongation rate of 17.4%.

ZrO₂ particle-reinforced copper-based friction materials were prepared by powder metallurgy (PM), and the effects of ZrO₂ contents on microstructure and properties of the materials were studied. The microstructure, density, porosity, hardness and friction and wear properties of the materials were characterized. The results show that the phase composition and distribution state of the copper base friction material are not changed significantly before and after the addition of ZrO₂ particles, and the ZrO₂ particles are evenly distributed in the matrix without agglomeration phenomenon. With the increase of ZrO₂ content, the density of the material decreases, the porosity increases, and the hardness tends to increase and then decrease. Under the test conditions of braking pressure of 1 MPa and rotation speed of 5 200 r/min, the friction factor and wear rate of the material decreases first and then increases with the increase of ZrO₂ content, and when the ZrO₂ addition reaches 8%, the friction and wear performance of the material reaches the best, the friction factor is 0.29, and the wear rate reaches the minimum value of 0.24 cm³/MJ.

Laser cladding was carried out to prepare Ni₃Al/Cr₇C₃ alloy coatings on 42CrMo steel. The effects of different Cr₇C₃ contents on the microstructure and wear resistance of the cladding materials were investigated using scanning electron microscopy, X-ray diffraction and wear tribometer. The results indicate that the microstructure of the Ni₃Al based cladding materials contains mainly Ni₃Al and in situ-formed Cr₇C₃. The microhardness of the laser cladding materials prepared by Ni₃Al/Cr₇C₃ alloy powder is above 550HV, and the maximum reaches 834HV. With the increase of Cr₇C₃ content, the wear resistance of Ni₃Al based cladding materials first increases and then decreases. When the Cr₇C₃ content is 25%, the wear rate of Ni₃Al based cladding materials is 0.74×10^-5 mm³/(N·m), only 14.7% of the wear rate of Ni₃Al laser cladding coating without Cr₇C₃, and the wear rate of Ni₃Al-based alloy cladding materials is only 1.669×10^-5 mm³/(N·m).

The 4J29 alloy formed by MIM underwent post-treatment through Hot Isostatic Pressing（HIP）at various temperatures. The study is aimed to explore how HIP temperature influences the microstructure, coefficient thermal expansion and tensile behavior of the 4J29 alloy. The results reveal a gradual increase in alloy density with rising HIP temperature. However, beyond 1 200 ℃, the density enhancement rate decelerates, hardness decreases, and grain size exhibits accelerated growth. The leak rate follows a trend of initial decrease, reaching its minimum at 1 200 ℃, and then increasing. Before 1 200 ℃, the leak rate decreases with temperature, and beyond 1 200 ℃, it gradually rises. The optimum HIP temperature is 1 200 ℃, resulting in the alloy reaching a density of 98.54%, a leak rate of 1.2×10^-9 Pa·(m³/s), hardness of 81.3HRB, an average thermal expansion rate of 2.0×10^-6 m·℃ between 30~200 ℃ and along with a noticeable enhancement in tensile strength and elongation.

In order to investigate the influence of alloy composition on the properties of soft magnetic alloy powders, 6 groups of alloy powders with varying contents of Si, Cr, and Mn were prepared by the water-gas atomization method. The saturation magnetization and coercivity of these alloy powders were characterized employing a vibrating sample magnetometer (VSM). Subsequently, the powder was compacted into magnetic powder cores, and their magnetic properties, insulation resistance, and corrosion resistance were evaluated using an LCR tester, a soft magnetic AC tester, and a salt spray tester. The results indicate that increasing the content of Si and Cr leads to a reduction in saturation magnetization and permeability. However, it significantly enhances coercivity, magnetic loss, insulation resistance, and corrosion resistance. Conversely, the incorporation of Mn into the alloy adversely affects saturation magnetization, permeability, coercivity, and hysteresis loss while improving eddy current loss and insulation resistance.

Particle size is an important factor affecting the performance of hydrogen storage alloy powders, and the abnormal fluctuation of particle size will lead to the decrease of the yield of Ni-MH battery negative electrode. The factors that may affect the particle size in the process of hydrogen storage alloy powder production were verified and analyzed, especially for the dry process of alloy powders, the key parameters of powder production equipment, analysis and testing equipment and sieve mesh were verified. The results show that the abnormal particle size distribution of the products in the pulverizing process has no obvious correlation with the pulverizing equipment and testing equipment, and the main cause of particle size problem is the deviation of wire diameter of screen used in pulverizing, and effective control measures are formulated accordingly.

Ultra-fine nickel powder was prepared by continuous feeding chemical vapor deposition method using NiCl₂·6H₂O as raw material. The effects of feeding rate and temperature on surface morphology of ultra-fine nickel powder were investigated. The laser particle analyzer, SEM and XRD were used to characterize the performance parameters. The results show that as the increment of feeding rate and temperature, the particle size of nickel powder gradually becomes larger, the particle size distribution is more uniform, the dispersion is better, the sphericity is higher and the crystallinity is stronger. But excessive increment in feeding rate and temperature results in the excessive growth of the particle size. The appropriate feeding rate and temperature are 135 g/h and 400 ℃ respectively.

Adopting improved Electrode Induced Gas Atomization (EIGA) technology, the feasibility of preparing spherical chromium powder by atomization is verified, and production efficiency is improved through process optimization. The effects of superheat and atomization pressure on powder particle size distribution and yield were focused. Scanning electron microscopy and Hall flowmeter were used to evaluate the morphology and flowability of spherical chromium powder. The results show that the sphericity of chromium powder prepared by EIGA method is over 98%. The optimal degree of superheat is 230-300 ℃. An increase in atomization pressure leads to a decrease in particle size. The yield of 15-53 μm powder is optimal at 5 MPa, and the efficiency far exceeds that of plasma method, while maintaining or surpassing the performance level of chromium powder prepared by plasma method.

The quality control issues associated with the reuse of titanium alloy powders in the Selective Laser Melting (SLM) technology for implantable medical devices was discussed. To address this issue, the concept of powder "circulation coefficient" is introduced, and a quantitative management method for the cyclic use of powders is established. Based on this, the physical properties, chemical composition, and mechanical properties of TC4 powders with circulation coefficients of 0, 7, and 14, and their specimens, were studied respectively. The results show that as the powder circulation coefficient increases, the performance of the powder and its prepared specimens changes in a significant, linear, and predictable manner. This verifies the feasibility and effectiveness of using the powder circulation coefficient as a quality control parameter during the recycling process of TC4 powders. Furthermore, the performance of the powder and its specimens gradually decreases during the recycling process of TC4 powders, which is related to an increase in the proportion of defective particles with excessive oxygen and nitrogen content.

Satellite powder is a common defect powder in metal powder preparation by atomization process. Excessive satellite powder defects affect the stability of powder laying and the density of the product. This paper starts from the principle of satellite powder defect formation by atomization process, and uses ANSYS Fluent to conduct numerical simulation in three-dimensional flow field. The influence of two novel atomization tower optimization structures formed by setting a mist protection cover and a supplementary gas device on the macroscopic airflow field in the tower were studied and the control effect of the flow field optimization structure on suppressing the formation of satellite powder was analyzed. The results show that the position and height factors of the mist protection cover affect the isolation effect of powder recirculation directly, and the position factor significant influences the distribution range of the recirculation area at the same time. Placing the mist protection cover structure of 300 mm height at a distance of 200 mm from the center axis and 250 mm from the top of the atomization tower can effectively isolate the direct impact of recirculating particles on the molten droplets in the atomization region. The pressure parameter of the supplementary gas device directly affects the isolation effect of recirculating particles and the intensity of recirculating gas clusters. Placing the supplementary gas device with a pressure parameter of 0.5 MPa at a distance of 200 mm from the center axis can provide good protection for the atomization region. Both of the two novel atomization tower optimization structures can effectively suppress the collision between particles and molten droplets in the atomization region ,thus achieving the effect of inhibiting the formation of satellite powder.

Adhesive wear and thermal ablation of copper-based friction plate easily occur under utmost conditions. The friction plates made of copper alloy-Cr-graphite-CeF₃ composites are prepared. The influences of Cr, nickel-clad graphite and CeF₃ on performances were researched by testing friction coefficient, impacting coefficient, wear rate and heat resistant coefficient under high load and speed conditions. The results show that appropriate content of Cr improves the hardness and strength of composites by dispersion strengthening and refined crystalline strengthening. The additions of nickel-clad graphite and CeF₃ improve the lubricating properties and wear resistance of the composites simultaneously by uniformly distributing on the friction surface. Meanwhile, nickel-clad graphite and CeF₃ improve the carry capacity of friction plates under heavy load and high speed conditions by improving heat resistant coefficient of composites. However, the excess Cr, nickel-clad graphite and CeF₃ are harmful to mechanical properties and wear resistance. After optimizing the contents of Cr, nickel-clad graphite and CeF₃, the friction plate possesses good mechanical properties, tribological performance and heat resistance, which improve the tribological performance and heat resistance of friction plates.

In response to the demand for lightweight structural materials in aviation, aerospace, high-end electronics and other fields, the application of particle reinforced aluminum matrix composites has been rapidly developed. However, at present, most of the research on aluminum matrix composites focuses on the preparation and analysis of small and medium size ingot, and the research on large size ingot and its properties and microstructure is less. The hot pressing billets with the volume fraction of 15%, 20% and 25% SiCp, the matrix alloy of 2009Al and the size of ϕ580 mm×730 mm were prepared by powder metallurgy, and the extrusion rod was extruded to ϕ250 mm. The density of the extruded rods is 100%, and the particle distribution is uniform. A small amount of Al₂Cu and Al₇Cu₂Fe are found by XRD analysis. The interface between SiCp and matrix was observed by TEM. It is found that SiCp and matrix are well combined, and no harmful interfacial reaction is observed. The tensile test at room temperature shows that the strength of the composite increases significantly with the increase of the volume fraction of SiCp. When the volume fraction of SiCp is 25%, the tensile strength of the composite is 630 MPa, the yield strength is 480 MPa, and the elongation is ≥3%. The tensile strength and yield strength of the composite are 20% and 25% higher than that of the matrix, respectively. The fracture modes of the three kinds of composites with SiCp content are dominated by the ductile fracture of the matrix alloy and the fracture of SiCp, and with the increase of the volume fraction of SiCp, the fracture phenomenon of SiCp increases significantly, and the fracture is more obvious, indicating that the high strength of the interface combination of SiCp and aluminum matrix makes SiCp plays a good bearing role.

With the amount of DEA as the knob to control the nucleation-growth rate of silver particles the high performance submicron spherical silver powder was prepared using hydroquinone and ascorbic acid to reduce silver nitrate by liquid chemical reduction method. The effect of DEA content on the properties of silver powder was studied. When the DEA content is 50% of the mass of silver nitrate, submicron spherical silver powder with average particle size D₅₀ of 0.49 μm, specific surface area of 2.3 m²/g, apparent density of 1.7 g/cm³ and burning loss of 0.35% could be obtained. By X-ray diffraction (XRD) and SEM analysis, silver powder has high purity, good crystallinity and high dispersion. After the silver powder is prepared into silver paste according to the formula, the measured viscosity is 38 Pa·S/25 ℃, after screen printing and low temperature curing. It is found that the lines are relatively dense and the edge lines are flat. The resistivity of the film cured at 200 ℃ is 8.70×10^-6 Ω·m.

With the increasing demand for high performance secondary battery energy density and safety performance, the development of new type of solid-state battery is a hot spot in the field of energy researches. The key part of solid-state batteries is the solid electrolyte, and the anti-perovskite type electrolyte Li₃OCl has attracted extensive attentions due to its wide voltage window and high ionic conductivity. In general, doping modification can further improve the ionic conductivity of Li₃OCl and stabilize its cubic phase structure. However, researches on lanthanum doping using rare earth elements are still lacking. China is rich in rare-earth reserves, so it is of great value to systematically study the application of rare earth elements in Li₃OCl based batteries. Herein, the effect of lanthanum doping by Nd element on ionic conductivity of Li₃OCl electrolyte was investigated. By precisely regulating the doping amount, the ionic conductivity of Li₃OCl can be successfully increased from 5.2×10^-4 S/cm to 8.3×10^-4 S/cm. The solid-state battery realized a stable cycling at the rate as high as 3C. The doping research of Nd in Li₃OCl can provide effective theoretical guidance for the development of high-power solid-state battery and the application on new energy vehicles.

Silicon carbide particle reinforced aluminum-silicon matrix composites have broad application prospects as structural functional materials in vehicle traffic, aerospace and precision instruments because of their high specific strength, high specific stiffness, good wear resistance and easy deformation. However, the coupling effect of thermal/stress field will occur in the preparation and processing of the composites, resulting in interface reaction, segregation of reinforcement phase, multi-scale precipitation of Si phase and intermetallic compound phase and microstructure evolution, which are unfavorable to the regulation of the mechanical properties of the composites. In this paper, the advantages and disadvantages of several mature preparation processes such as powder metallurgy, stir casting, impregnation and jet deposition are reviewed, and the effects of several preparation processes on the microstructure and properties of composites are analyzed

Hot isostatic pressing (HIP) technology can be used in powder metallurgy to manufacture high-performance components, and in recent years, it has been widely applied in the fields of casting densification, diffusion bonding, and near-net-shape forming. As a green and efficient component preparation technology with simple processes and controllable properties, hot isostatic pressing powder metallurgy (HIP-PM) will be widely used in numerous industrial fields in the future, such as aerospace, nuclear power engineering, electronic information, rail transit, etc. The research progress of HIP-PM technology for duplex stainless steel (DSS) from aspects such as DSS powder preparation, the microstructure and mechanical properties of products are introduced, and corrosion resistance and the application fields and development trends of this technology are summarized.

Additive manufacturing of 316L stainless steel has broad application prospects in the field of nuclear energy due to its excellent processing accuracy, surface quality, comprehensive mechanical properties, and corrosion resistance. However, when nuclear structural materials are used in irradiation environments, the defects generated by irradiation can lead to a decrease in material performance. In order to ensure the stability of the performance of AM 316L stainless steel under irradiation environment, the study of its irradiation damage effect has gradually become a hot topic of attention both domestically and internationally. Therefore, the research progress on the structure, properties, and radiation resistance of AM 316L stainless steel commonly used in the field of nuclear energy is reviewed, and some suggestions for future research directions are proposed in the article.

The forming process of the shape and structure of a certain electrical adjustment seat component was analyzed, and Moldflow software simulation results was used to guide the improvement and optimization of the gate type and position in the design scheme of the metal injection molding mold. Finally, the design of the metal injection molding mold is completed. Through actual production verification, the mold structure is reasonable, and the product quality of injection molding using this mold meets customer′s requirements.