A novel multicomponent alloy, V_2.5Cr_1.2WMoCo_0.04, produced from elements expected to favour a BCC crystal structure, and to be suitable for high temperature environments, was fabricated by arc melting and found to exhibit a multiphase dendritic microstructure with W-rich dendrites and V–Cr segregated to the inter-dendritic cores. The as-cast alloy displayed an apparent single-phase XRD pattern. Following heat treatment at 1187 °C for 500 h the alloy transformed into three different distinct phases - BCC, orthorhombic, and tetragonal in crystal structure. This attests to the BCC crystal structure observed in the as-cast state being metastable. The radiation damage response was investigated through room temperature 5 MeV Au⁺ ion irradiation studies. Metastable as-cast V_2.5Cr_1.2WMoCo_0.04 shows good resistance to radiation induced damage up to 40 displacements per atom (dpa). 96 wt% of the as-cast single-phase BCC crystal structure remained intact, as exhibited by grazing incidence X-ray diffraction (GI-XRD) patterns, whilst the remainder of the alloy transformed into an additional BCC crystal structure with a similar lattice parameter. The exceptional phase stability seen here is attributed to a combination of self-healing processes and the BCC structure, rather than a high configurational entropy, as has been suggested for some of these multicomponent “High Entropy Alloy” types. The importance of the stability of metastable high entropy alloy phases for behaviour under irradiation is for the first time highlighted and the findings thus challenge the current understanding of phase stability after irradiation of systems like the HEAs.

一种新型多组分合金V _2.5 Cr _1.2 WMoCo _0.04，是通过电弧熔化制造的，这种合金由预期会有利于BCC晶体结构并适用于高温环境的元素制成，并显示出具有富W枝晶的多相枝晶显微组织。 V-Cr分离到树突间核心。铸态合金显示出明显的单相XRD图。在1187°C热处理500 h后，合金转变为三个不同的相-BCC，正交晶和四方晶的晶体结构。这证明了在铸态下观察到的BCC晶体结构是亚稳态的。在室温5 MeV Au ⁺下研究了辐射损伤响应离子辐射研究。亚稳态铸态V _2.5 Cr _1.2 WMoCo _0.04对每个原子（dpa）高达40位移的辐射损伤具有良好的抵抗性。如掠入射X射线衍射（GI-XRD）图所示，铸态的96％的单相BCC晶体结构保持完好无损，而合金的其余部分转变为具有相似晶格的其他BCC晶体结构参数。此处看到的出色的相稳定性归因于自愈过程和BCC结构的结合，而不是像某些多组分“高熵合金”类型所建议的那样具有高组态熵。