Preparation of Ti-6Al-4V feedstock for titanium powder injection molding

Abstract

Titanium powder injection molding (Ti-PIM), combining the advantages of both powder metallurgy and plastic injection molding, is an effective manufacturing technology for a near net shape production of titanium parts. In this work, titanium feedstock was fabricated by mixing the pre-alloyed Ti-6Al-4V powder with a wax-polymer binder system after determining their critical solid loading percentage. The rheological and binder decomposition behaviors of prepared feedstock were investigated. The results showed that the feedstock had a critical solid loading of 71 vol. % and the flow activation energy for fabricated feedstock was 64 kJ/mol. The binders were decomposed with two sigmoids functions, where the activation energies for the first and second sigmoid decomposition were 68 kJ/mol and 224 kJ/mol, respectively. The results indicated that the Ti-6Al-4V feedstock was well prepared and would provide good rheological and thermal decomposition behaviors for injection molding and thermal debinding process in Ti-PIM.