以单聚合物组元石蜡基粘结剂PW-EVA和PW-HDPE作为对比，选择具有良好喂料流变学性能的PW-EVA-HDPE多聚合物组元石蜡基粘结剂，研究其脱脂保形性和分步快速脱脂过程。研究结果表明：采用分步快速脱脂曲线，PW-EVA-HDPE 粘结剂中的PW、EVA、HDPE 可分别在350℃、420℃、500℃有序地分为3步依次脱除，该粘结剂体系具有最佳的脱脂保形性能。

研究了具有不同聚合物组元的几种石蜡基粘结剂和喂料的流变学性能及脱脂性能，比较了聚合物组元对其流变学性能、脱脂性能及产品力学性能和尺寸收缩性能的影响，结果表明，采用HDPE和EVA组合作为聚合物组元的PW-HDPE-EVA粘结剂具有最优性能。

The application of PIM (powder injection molding) process of cemented carbide parts bas been studied. Two kinds of cemented carbide powders, with the particle size of 3um and 0.4um respectively, were used in the experiments. Two kinds of binders were applied. The rheological properties of feedstocks were studied. The thermogravimetry analysis and thermal debinding cycles were investigated. Possible defects introduced in PIM process steps were described. The influences of holding temperature and holding time during debinding on the carbon content in compacts were studied. The mechanical properties of cemented carbide parts prepared with different partiele sized powders were compared.

Four kinds of Fe-2Ni metal injection moulding (MIM) feedstocks with the same powder loading and with similar binder composition except for minor components were prepared and their viscosities at different temperatures and shear rates determined using a capillary rheometer. The flowabilitv and the sensitivity of viscosity to shear rate and temperature were investigated. The viscosities of the binders and the general theological indices of feedstocks were compared. The results show that the minor com- ponents of the binders play a very important role in the rheology of feedstocks. A feedstock based on a PW PP binder can not be used for injection mould-ing owing to severe powder binder separation. A feed-stock based on a PW EVA binder has the lowest viscosity and is the easiest to flow into the mould. The viscosity of a feedstock based on a PW EVA HDPE binder is higher than that of a feedstock based on the PW EVA binder and is lower than that of a feedstock based on a PW HDPE binder. The general rheolog-ical index, which includes the effect of flowabilitv and the sensitivity of viscosity to shear rate and temper-ature, can be used to evaluate the general theological properties of MIM feedstocks. At a reference temper-ature of 150℃ and reference shear rate of 1181 s-1. the general rheological indices for the feedstocks based on the PW-EVA. PW-HDPE, and PW-EVA-HDPE binders are 7-8. 4-0. and 93 respectively. The feedstock based on the PW EVA HDPE binder has the best general rheological properties and is most suitable for injection moulding. The mechanical prop-erties and shrinkage homogeneity of MIM tensile bars prepared with the feedstock based on the PW EVA HDPE binder are also the most acceptable.