WC Grain Growth Behavior During Selective Laser Melting of WC–Co Cemented Carbides

Abstract

Scanning strategy is a critical parameter for selective laser melting (SLM) processing of metals, alloys as well as metal-ceramic composites, while related research has rarely been reported yet, especially for additive manufacturing of WC–Co cemented carbides. In this study, three scanning strategies, i.e., stripe, checkerboard, and spiral scanning, were used for additive manufacturing of WC-32Co cemented carbides. Checkerboard scanning leads to the highest relative density of 96%. Stripe scanning results in the largest average WC grain size followed by checkerboard and spiral scanning. SLM-processed carbides demonstrate agglomeration of WC grains mixed with isolated Co pools and pores. The WC grain growth mechanisms of SLM-processed cemented carbides include mosaic agglomeration growth and incomplete and uneven step growth regardless of scanning strategies.