Critical solid loading is a composition where the particles are tightly packed without external pressure and the binder filled the entire spaces and voids between the particles. The aims of this study is to determine the critical powder volume concentration (CPVC) and to investigate the influence of the different powder loadings, mixing behavior and energy for magnesium metal injection molding feedstock. The present mixing study was conducted for magnesium (Mg) powder with different compositions of binder consist of paraffin wax (PW), high density polyethylene (HDPE), and stearic acid (SA). The result showed CPVC of Mg powder obtained was 69 vol.%. Result reveals that an increasing in the ratio of powder-binder will disturb the viscosity of the feedstock. The relative viscosity increased with increasing the powder loading and approach to infinite near to the critical solid loading. Besides, the processing temperature, totalized torque (TTQ) and energy involved in the mixing process also increased as powder loading increased.
