Fabrication of WC Cemented Carbide Molding by Preparation of WC/Co HVOF coating on Base Plate

Cemented carbide represented by WC-Co has been applied in various industrial tool fields such as jig, mold and cutting tools due to its high hardness and toughness. Generally, to produce those tools, conventional powder-metallurgical processing and special cutting tool manufacturing are time-consuming, expensive and design restrictions. Cemented carbide industries desire to shorten delivery time and free space design of those tools by applying additive manufacturing processes. However it is difficult to form cemented carbide object due to peeling off from metal base plate during the process by powder bed fusion with selective laser melting. This study focuses on the cause of detachment between baseplate and molded objects compared by coefficient of thermal expansion, intermediate layer on baseplate. Thermal sprayed WC/Co intermediate layer on Stainless steel baseplate resulted works as baseplate for WC/Co moldings. The aim of this study is to understand the mechanism of detachment prevention by WC/Co thermal spray coating by comparison of coefficient of thermal expansion, crystal phase, surface texture and layer structure.