FLOW BEHAVIOR OF CERAMIC INJECTION-MOLDING SUSPENSIONS

The yield stress of seven A16.SG alumina suspensions was estimated using shear stress-shear rate data measured at the processing temperature. Five of these were processed using a high molecular weight polypropylene binder system but each have a different %vol. of ceramic. The two other formulations contain a low molecular weight alcohol as the major binder. The relative viscosities of the A16.SG alumina-polypropylene compositions were used in an extended form of the Eilers equation to evaluate, V(max), the maximum volume fraction of ceramic. The relative viscosities of three other alumina powders processed using the same polypropylene binder system were also investigated using the same equation in order to assess the effect of particle characteristics on V(max).