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The powder–binder separation is a common difficulty during injection molding, which leads to the inhomogeneity in the debinding and sintering stages. Previous studies focus on the relationship between “final results” and “initial conditions”, while the dynamic filling process of feedstock and the evolution of powder–binder separation were ignored. This work investigated the effects of filling patterns on the powder–binder separation during powder injection molding. The mold filling model of PIM has been developed, based on the multiphase fluid theory and the viscosity model of feedstock. Parameters of the viscosity model were modified by the experimental data. Numerical simulations were compared with experiments with the same process parameters. The powder–binder separation phenomena in green bodies were detected by X-Ray computed tomography (CT). The experimental phenomena were explained clearly by the evolution of powder–binder separation obtained with numerical simulation method. A typical compacting filling pattern of PIM and filling mobility variable of the feedstock were proposed. A proper filling pattern was helpful to ensure the mobility of feedstock and the homogeneity of green body.

University of Science and Technology Beijing (USTB) is one of the key universities that are directly under the guidance of China Ministry of Education. Powder metallurgy activities have been carried out at USTB for about 50 years. Beijing Key Laboratory for Advanced Powder Metallurgy and Particulate Materials, which was founded on the base of Department of Powder Metallurgy at USTB, is a comprehensive base for PM education, research and development in China. In this paper, some of the current research activities and achievements in this laboratory are introduced, including ultra-fine grained cemented carbides made from nanometer powders, W-Cu and Mo-Cu alloys for electronic packages, SHS process and its applications, warm compaction, and powder injection molding.