Promoted room-temperature deformability and high-temperature strength synergy through zig-zag faceted interface design in TiNbTaWC0.7 eutectic refractory high-entropy alloy

Abstract

With the development of aerospace technologies, there is an urgent demand for materials with better high-temperature performance. Despite the bottleneck of combining high-temperature strength and room-temperature deformability, refractory high-entropy alloys are potential candidates. Here, we report a novel alloy, TiNbTaWC0.7, with a good strength-ductility synergy by introducing the eutectic carbide phase. The alloy is composed of alternated BCC matrix phase and FCC carbide phase, forming a fully eutectic microstructure. With the introduction of the eutectic carbides, the alloy is robust at 1200 °C. The faceted phase interface together with the compositional complex carbides provides the alloy with good deformation ability at room temperature. The former promotes dislocation nucleation and transmission, and the latter generates stacking faults by partial dislocation movement. This strategy provides a new route to design promising high-temperature structural materials by combining the advantages of eutectic alloy, carbide strengthening, and refractory alloys utilizing the high entropy concept.

Keywords

• Eutectic alloy
• Refractory high-entropy alloy
• Microstructure
• Mechanical property