Ultrastrong irradiation-resistant low-activation multi-principal-element alloy with wide-temperature-range applicability

Developing clean energy via fusion reactors critically demands low-activation materials with excellent mechanical properties and high irradiation resistance at varying temperatures. However, previous materials can hardly fulfill the associated multi-performance requirements, let alone when pursuing these at relatively low cost. Here we introduce a strategy to overcome this challenge by blending thermally stable dispersive coherent Laves nanoprecipitates into highly distorted body-centered cubic (BCC) solid solution matrix in a low-activation and cost-effective FeCr-rich multi-principal-element alloy (MPEA) containing multiple refractory elements (e.g., V, W, and Ta). The low mixing enthalpies together with the high atomic-size and modulus mismatches in the MPEA enable the coherent nanoprecipitates with core-shell structure and the highly distorted lattice in the BCC matrix, significantly enhancing the microstructural thermal stability. The synergistic effects of significant nanoprecipitation and solid-solution strengthening at maintained deformability are favored by non-screw dislocations in a wide temperature range (25–1000 °C). Moreover, dispersive nanoprecipitates and highly distorted BCC lattice in the MPEA empower high irradiation resistance by promoting defect re-annihilation and hindering defect formation. The work thus provides an important avenue for designing low-activation high-strength irradiation-resistant materials at relatively low cost for wide-temperature-range applications.