Investigation of Microstructure and Properties in WTaVCrTi0.1 High-Entropy Alloy

This study successfully prepared a new type of WTaVCrTi0.1 refractory high entropy alloy (RHEA) by vacuum levitation melting (VLM), and systematically studied its microstructure, mechanical properties and thermal shock properties. The phase analysis of XRD and TEM confirms that the alloy forms a single-phase body-centered cubic (BCC) solid solution. All constituent elements are uniformly distributed at the macroscopic scale without significant segregation. At the microscale, a characteristic dendritic segregation pattern is observed, exhibiting a continuous and complementary partitioning behavior consistent with non-equilibrium solidification. The alloy shows excellent mechanical properties. The yield strength at room temperature can reach 1752 MPa, and it still maintains a high strength (≥1140 MPa) at 800°C. The microstructural characterization shows that it has refined equiaxed grains and weak orientation, which significantly improves the anisotropic deformation performance and crack resistance. The transient thermal shock test conducted at 0.20 GW/m² and 0.40 GW/m² power densities shows that WTaVCrTi0.1 alloy has better crack propagation resistance than WTaVCrTi0.2. With excellent thermal stability, high-temperature strength, and superior thermal shock resistance, WTaVCrTi0.1 alloy can become an ideal candidate for plasma materials of fusion reactors. • A novel low-activation WTaVCrTi 0.1 refractory high-entropy alloy is fabricated via vacuum levitation melting. • The alloy forms a chemically homogeneous single-phase BCC solid solution with refined equiaxed grains. • It exhibits ultra-high yield strength of 1752 MPa at RT and retains 1140 MPa at 800°C. • The alloy shows superior thermal shock resistance with suppressed crack propagation at 0.40 GW/m². • The work demonstrates its great potential as a plasma-facing material for fusion reactors.