Microstructure evolution of WC-20Co cemented carbide during direct selective laser melting

The feasibility of selective laser melting (SLM) was investigated for manufacturing WC-20Co cemented carbide in this study. Both the microstructure analysis and finite element simulation were used to investigate the sintering mechanisms of cemented carbides during SLM process. Characterisation of WC grain size and distribution for SLM processed cemented carbides, as well as the finite element simulation, was conducted. It was shown that during SLM processing, extremely high sintering temperature combined with the short soaking time contributes to the unique inhomogeneous microstructure and densification behaviour of cemented carbide samples. The synergy of laser power and scanning speed determines the maximum sintering temperature during SLM processing.