Master flow curves as a tool to modelling ceramic injection molding

Compounds used for Ceramic Injection Molding (CIM) are rheologically complex materials. The applicability of currently available mathematical models to CIM systems fails due to high number of variables playing a significant role: binder composition, powder morphology and loading as well as concentration of processing aids. In this paper we present the way to overcome this issue with a model, where a set of its parameters is a priori given regardless the contents of powder or additional ingredients in a feedstock. Then, the relative viscosity of an individual composition of a CIM feedstock is obtained only by inserting the corresponding concentrations of powder (aluminium oxide) and additive (stearic acid). The proposed master curve exhibits the fixed functional structure common for 36 composition combinations arising from Al2O3 powder loading (0-50%) and stearic acid concentration (up to 5%). The deviation from the measured values does not exceed an experimental error.