The rheological and shape retention properties of wax2based binders with different polymer components were studied. The effects of different polymer components on rheological, shape retention and me-chanical properties, and isotropic dimension shrinkage were investigated. The feedstock based on the PW-PP binder can not be used for injection molding due to severe separation of the binder from metal powder. The general rhelogical properties of the Fe-2Ni feedstock based on the PW-EVA binder were superior to that of the Fe-2Ni feedstock based on the PW-HDPE binder, while the shape retention properties of the PW-HDPE binder were superior to that of the PW-EVA binder. By the combination of EVA and HDPE as multi-polymer components, the PW-EVA-HDPE binder should have the best rheological and shape retention properties. The shrinkage homogeneity and mechanical properties of the feedstock based on this binder were also the best.

从材料的综合流动曲线及聚合物、粘结剂的流动性能，分析了金属注射成形喂料的流动行为，给出了用毛细管粘度计测量金属注射成形喂料粘度并确定其流动曲线参数的分析方法。

97W-2Ni-1Fe heavy alloy feedstocks with different powder loadings were prepared for injec-tion molding. The rheological behavior of these feedstocks was studied. The mechanical properties of as-sintered parts and the shrinkage during sintering were measured. The results showed that the rheological be-havior of these feedstocks could be described as pseudoplastic fluid. The mechanical properties of the injection molded alloy are superior to those of alloy prepared by conventional press/ sinter process. There is an optimal powder loading 47% (volume fraction) with the best mechanical properties. The shrinkage during sintering is isotropical and the tolerances of products are small.

The process of thermal debinding of injection molded water atomized 316L stainless steel powder compacts was studied in a vacuum and hydrogen atmosphere using a mercury porosimetry and the thermogravimetric analysis method. The vacuum debinding rate was investigated under the conditions of different binder compositions and temperature-increase rates, especially at the low temperature stage. The process of thermal debinding in the hydrogen atmosphere was compared with that in vacuum. It was found that the binder removal rate was much higher in vacuum than that in the hydrogen atmosphere under the same experimental conditions. The mercury porosimetry was used to measure the pore structure evolution. The results of the mercury porosimetry indicated that the pore structure evolution in injection molded compacts during thermal debinding in vacuum was greatly different from that in hydrogen atmosphere. A fine inter-connected pore structure developed as a result of the evaporation and removal of the low molecular binder components at the early stage of debinding. The reason for the difference in binder removal rate and the inter-connected pore structure in these two debinding environments lies in the difference of the vapor pressure drop, which was the vapor pressure difference between that in the molded compacts and that in the ambient environment. At the different thermal debinding stages and environments, the pore structure evolution and changes in the mean pore size in the thermally debound compacts were also different. From the low debinding temperature stage to the intermediate temperature stage of about 300 8C, the pores in the thermally debound compacts in the hydrogen atmosphere were finer and the pore size distribution was more homogeneous than that in the vacuum. At the final debinding stage, the pore size distribution was almost the same in the hydrogen atmosphere as in the vacuum.

采用MIM（金属注射成形）标准拉伸试样模具，研究注射过程主要工艺参数即注射温度、注射压力、模具温度对注射过程缺陷的影响， 获得了最佳注射工艺参数。对欠注、断裂、中心通孔等几种缺陷的形成机制作了分析，并提出了MIM成形范围图的概念。