Mechanical properties and fracture characteristics of CNTs-doped W–Nb alloys

Abstract W-based alloys are currently considered promising candidates for high heat flux components in future fusion reactors. In this work, the strength and fracture toughness of CNTs-doped W–Nb alloys fabricated by hot pressing were measured by three-point bending tests on smooth and single edge notched beams, respectively, and the fracture characteristics were observed by scanning electron microscopy. The result indicated that the bending strength and fracture toughness increased with increasing the Nb content. Combining with the microstructure analysis on the fracture surface, it was found that the increased Nb content could refine the microstructure and form the oriented Nb(W) solid solutions, which increases the number of crack deflections and total fracture paths and enhanced the strength and fracture toughness.