An ultrastrong niobium alloy enabled by refractory carbide and eutectic structure

Nb alloys with high strength and relatively low density are sought for high-temperature applications. However, due to strain softening, conventional Nb alloys often exhibit insufficient high-temperature strengths. Here we report a strategy to design a novel lightweight and thermally-stable Nb alloy by combining the notion of eutectics and refractory carbide. The resulting Nb2MoWC0.96 eutectic alloy exhibits a high-temperature specific compressive strength of 77.2 MPa/·cm3·g1 at 1673 K with a retained engineering plasticity of 37.5%, both are notably higher than the existing Nb and Nb-containing alloys. This work demonstrates that both the strength and plasticity of Nb alloys can be further optimized with refractory carbide and eutectics.