【摘要】 研究了Al-Li-Mg-Ti-M（M=Zn,Zr,V）轻质高熵合金（LW-HEAs）的显微组织演变、相稳定性和力学性能。根据HEA的热力学设计标准设计了Al₂₀Li₂₀Mg₁₀Ti₄₀Zn₁₀ （#Zn）、Al₂₀Li₂₀Mg₁₀Ti₃₀Zr₂₀ （#Zr）和Al₂₀Li₂₀Mg₁₀Ti₃₀V₂₀ （#V）3种成分的LW-HEAs，并通过机械合金化和冷压烧结相结合的方法制备了这3种合金。研究了合金成分及烧结温度对LW-HEAs显微组织和力学性能的影响。结果表明，球磨后的Al-Li-Mg-Ti-M （M=Zn,Zr,V） LW-HEAs分别形成了以HCP型固溶体为主要相、双HCP型固溶体相和BCC相的简单结构。经过冷压烧结后，#Zn和#V合金发生了明显的相变；而含有双HCP相的#Zr合金在热处理过程中的相稳定性最好。在BCC相固溶强化和β-AlTi₃沉淀强化的共同作用下，#V-750℃合金的硬度和比强度最高，分别达到HV 595.2和625 MPa·cm³/g。#Zr-650℃、#Zr-750℃、和#Zn-650℃合金有望具有优异的塑性。更多还原

【Abstract】 The microstructural evolution,phase stability,and mechanical properties of Al-Li-Mg-Ti-M （M=Zn,Zr,V）lightweight high-entropy alloys （LW-HEAs） were investigated.The LW-HEAs with three components,Al₂₀Li₂₀Mg₁₀-Ti₄₀Zn₁₀ （#Zn）,Al₂₀Li₂₀Mg₁₀Ti₃₀Zr₂₀ （#Zr）,and Al₂₀Li₂₀Mg₁₀Ti₃₀V₂₀ （#V）,were designed according to the thermodynamic design criteria of HEA,and prepared via a combination process of mechanical alloying and cold-press sintering.The effects of alloy composition and sintering temperature on the microstructure and mechanical properties of the LW-HEAs were studied.The results show that the as-milled Al-Li-Mg-Ti-M （M=Zn,Zr,V） LW-HEAs form a simple structure with HCP-type solid solution as the primary phase,a dual-HCP type solid solution phase,and a BCC phase,respectively.After cold-press sintering,the#Zn and#V alloys undergo obvious phase transformation;while the#Zr alloy with dual-HCP phases exhibits the best phase stability during heat treatment.The#V-750°C alloy demonstrates the maximum hardness and specific strength of HV 595.2 and 625 MPa·cm³/g,respectively,under the combined effect of solid solution strengthening of BCC phase and precipitation strengthening of β-AlTi₃.Moreover,the#Zr-650°C,#Zr-750°C,and#Zn-650°C alloys are expected to have excellent plasticity.更多还原