Optimization of Injection Molding Parameters for WC-Co Feedstocks

This study investigates the effect of injection molding parameters on the density of green body of cemented carbide (WC-Co) – based powder injection molding (PIM) feedstock. Experiments were conducted with ball-milled WC-Co powder mixed with a palm stearin and polyethylene binder system. To minimize the test run while maintaining the quality standard of data measurement, design of experiment approach, particularly Taguchi Method with L18 orthogonal array was used in the present study. Several parameters were considered, namely, powder loading, injection temperature, holding pressure and injection rate, while density of the green body as the response factor. The results show the optimum combination of injection factor that produces the best green density value, which eventually will leads to higher density for sintered parts.