Influence of binder composition on the rheological behavior of injection-molded microsized SiC suspensions

The influence of four kinds of binders consisting of paraffin wax (PW), random-polypropylene (RPP), high-density polyethylene (HDPE), and stearic acid (SA) on the rheological behavior of injection-molded SiC feedstocks was investigated over a temperature range of 150°C to 180°C and a shear rate range of 4 s−1 to 1259 s−1. The results showed that all the feedstocks exhibited pseudoplastic flow behavior. The wax-based binder of multipolymer components (PW-RPP-HDPE) exhibited better comprehensive rheological properties compared with the binder of monopolymer components (PW-RPP or PW-HDPE). The addition of 5wt% SA to the binder could reduce the viscosity of the feedstock but enhance the rheological stability by improving the wettability between the binder and the SiC powder. The binder of 65wt% PW + 15wt% HDPE + 15wt% RPP + 5wt% SA was found to be a better binder for microsized SiC injection molding.