Surface adhesion between ceramic injection molding feedstocks and processing tools

Interfacial adhesion between highly filled aluminum and zirconium oxides ceramic compounds and CIM (Ceramic Injection Molding) processing tools was investigated from contact angle measurement. Polymers considered as binder components were low density polyethylene, paraffin wax, polyethylene glycol, carnauba wax, acrawax, and stearic acid. Channel walls of the mold were constructed from hardened, TiN hardened, nitridized and heat-treated steels. From the calculated surface energies, the superiority of heat-treated steel as well as acrawax and especially polyethylene glycol as binders is derived. Carnauba wax shows similar wettability as stearic acid, thus becoming promising substitute for the role of processing aid. Concerning tested ceramic powders, Al2O3 revealed somewhat higher polar component of the surface energy than ZrO2. The differences in total surface energies of powders and binders are all about 3 J/m2 lower (PEG) or higher (PW, LDPE, AW, CW, SA) for Al2O3 powder than for ZrO2.