Near crack free additive manufacturing of a novel W-Nb-C alloy

Abstract

The high ductile brittle transition temperature of tungsten (W) poses challenges like cracking and porosity during its laser-powder bed additive manufacturing (L-PBFAM). Computational alloy design evaluated niobium (Nb) and carbon (C) to activate eutectic solidification, addressing the cracking issues during the terminal stage of solidification. Furthermore, these elements prevent O segregation at grain boundaries, thereby enhancing grain boundary cohesion in W. In combination with effective process parameters, the novel W-Nb-C alloy developed for L-PBFAM produces near crack-free specimens with heterogeneous microstructures. The intrinsic mechanical responses associated with the heterogenous microstructure were delineated by nanoindentation analysis.

Keywords

• Tungsten alloy
• alloy design
• laser-powder bed additive manufacturing
• nanoindentation