Material extrusion-based three-dimensional printing of WC–Co alloy with a paste prepared by powder coating

Abstract

Production of WC–Co alloys by casting is challenging because they have high melting points; therefore, they are mainly manufactured by powder metallurgy. In this study, the WC–Co alloy was produced by material extrusion three-dimensional printing. A paste with a high solid content was prepared, and the composition of the paste was optimized by rheological characterizations according to the contents of the dispersant, solvent, and binder. A binder coating on the surface of the powder was used to increase the homogeneity of the paste. Thus, a paste with a solid content of 54 vol% was prepared, and a sintered sample with a relative density of 99% was achieved by sintering at 1400 °C in vacuum. The hardness and fracture toughness were measured to be 16.5 GPa and 16.5 MPa·m0.5, respectively, which is similar to those of the WC–Co products manufactured by powder metallurgy. This method will increase the degree of freedom of shape and significantly enhance the production time and economic efficiency, particularly in the development stage of new products