Powder metallurgy technology has the advantages of low cost, low energy consumption and high material utilization rate. In addition, process parameters can be adjusted in a larger range during the process of powder metallurgy. Therefore, it has been widely used in machinery, aviation, medical treatment and other fields. The manufacturing process can be divided into four steps, including powder preparation, mixing, compaction and sintering, among which the last two are critical for densification and decisive for the performance of composite material. However, it is hard to observe the dynamic densification changes of powders directly for traditional experimental method, which makes it more difficult to investigate the micro-mechanism of particle rearrangement and deformation. Still, computer numerical simulation can reach visualization during the compaction and sintering stages. In recent years, there have been surging researches of numerical simulation on powder compaction, but few on sintering. Theoretical models and modeling methods varies with each research object, from person to person. In this paper, theoretical models of numerical simulation in powder metallurgy are briefly described, involving ellipsoidal yield criterion and unified constitutive model both based on elastoplasticity behavior, rheological theory focusing on particle and rheological properties, endochronic plasticity theory with endochronic measurement reflecting the magnitude of nonlinear strain, etc. Common modeling methods including finite element method reflecting deformability, discrete element method based on particle characteristics, and multi-particle finite element method combining the above two, are also discussed. In addition, the chief problems and status of current powder sintering process are clarified. This review is expected to be referable for the numerical simulation of powder metallurgy. © 2022 Cailiao Daobaoshe/ Materials Review. All rights reserved.
