IMPROVEMENT OF RHEOLOGICAL AND SHAPE RETENTION PROPERTIES OF WAX-BASED MIM BINDER BY MULTI-POLYMER COMPONENTS①
(The State Key Laboratoryfor Powder Metallurgy,Central South University of Technology, Changsha 410083, P. R. China)
Abstract: The rheological and shape retention properties of wax-based binders with different polymer components were studied. The effects of different polymer components on rheological, shape retention and mechanical 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.
Key words: rheological property metal injection molding (MIM) binder polymer component