Additive Manufacturing of WC–Co Hard Metals Using Laser Powder Bed Fusion

Laser based additive manufacturing of cemented carbides remains challenging due to crack forming and residual porosity. Reduction of temperature gradients and successive thermal treatment are starting points for improving the quality of the additive manufactured parts. In this study, the build-plate was heated to 900 °C during Laser Powder Bed Fusion (LPBF). Sinter-HIP was used for thermal post-treatment of the LPBF samples. The influence of the process parameters during laser powder bed fusion is reduced by thermal post-treatment. Significant grain growth and broader grain size distribution are observed in tungsten carbide (WC) phase. Thermal post-treatment should be included in the process chain for additive manufacturing of cemented carbides, as porosity is reduced using sinter-HIP technique to a minimum.