Abstract A nanoscale sigma (σ) phase strengthened Co34.5Cr30Ni26.5Al5.4W3.6 (at, %) high entropy alloy was prepared and showed high strength and ductility. Dual phase microstructure that comprises face-centered cubic (FCC) matrix and nanoscale σ particles was obtained after thermomechanical procedures. The excellent ductility is attributed to its high strain hardening exponent FCC matrix that strongly favors uniform deformation and prevents crack propagation. The alloy shows an extremely high strain hardening rate and strength due to the interactions between the σ particles, deformation twins and dislocations. The design concept of “deformation twins + nano particles” should be considered for the design of additional double-high (strength and ductility) FCC HEAs in future work.

中文翻译：

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一种纳米σ相强化的延性高熵合金

摘要 制备了一种纳米级σ(σ)相强化Co34.5Cr30Ni26.5Al5.4W3.6(at,%)高熵合金，该合金具有较高的强度和延展性。在热机械程序后获得包含面心立方 (FCC) 基体和纳米级 σ 颗粒的双相微结构。优异的延展性归因于其高应变硬化指数 FCC 基体，该基体强烈有利于均匀变形并防止裂纹扩展。由于 σ 粒子、变形孪晶和位错之间的相互作用，该合金显示出极高的应变硬化速率和强度。在未来的工作中，额外的双高（强度和延展性）FCC HEA 的设计应考虑“变形孪晶+纳米颗粒”的设计理念。