Shape retention and infiltration height in complex WC-Co parts made via binder jet of WC with subsequent Co melt infiltration

Abstract

Additive manufacturing (AM) of complex tungsten carbide-cobalt (WC-Co) parts was achieved using binder jet additive manufacturing (BJAM) of WC powders followed by Co infiltration. The intent of the study is to explore the shape retention, infiltration height, and properties of parts made with this method. Using BJAM with infiltration of the metal phase can limit shrinkage and grain growth in ceramic-metal (cermet) composites compared to other additive manufacturing (AM) methods. Knowledge of previous infiltration studies was used to help process parts to imitate production of parts. The properties such as density, microstructure, grain size, and hardness of the parts are characterized along the infiltration height. Fracture toughness is measured where applicable. This approach has the potential to achieve highly dense WC-Co parts that are net-shaped with some ternary phase and z-direction distortion.