AlCrFeCuNi高熵合金力学性能的分子动力学模拟

高熵合金具有传统合金无法比拟的高强度、高硬度和高耐磨耐腐蚀性,具有广阔的应用前景。为研究AlCrFeCuNi高熵合金(High entropy alloy,HEA)在轴向载荷作用下的力学性能,采用分子动力学方法,模拟高熵合金的实验制备过程并建立原子模型,研究温度和Al的含量对AlCrFeCuNi高熵合金力学性能的影响,从材料学角度分析了变形过程及其具有高塑性的原因。模拟结果表明,AlCrFeCuNi高熵合金在拉伸载荷作用下依次经历弹性、屈服、塑性3个变形阶段。在屈服阶段,开始出现孪晶和层错,孪晶和层错的产生和生长是合金产生不均匀塑性变形的主要原因之一。高熵合金的杨氏模量和屈服应力随着Al含量的增加近似线性降低,同时具有很强的温度效应,温度越低,Al含量越小,其杨氏模量和屈服应力的下降幅度越大。

Mechanical Properties of AlCrFeCuNi High Entropy Alloy:A Molecular Dynamics Study

High entropy alloy(HEA)has high strength,high hardness,high wear resistance and corrosion resistance which traditional alloys do not have,and has broad application prospects.The mechanical properties of AlCrFeCuNi high Entropy Alloy(HEA)under axial loading were also studied in this paper.Molecular dynamics method was used to simulate the experimental preparation process of HEA and establish an atomic model.The mechanical properties of AlCrFeCuNi HEA at different temperatures and Al concentrations were studied.The deformation process and the reasons for its high plasticity were analyzed from the point of view of material science.The simulation results show that the AlCrFeCuNi HEA undergoes elastic deformation,yield and plastic deformation stages under tension loads.In the yield stage,the appearance and growth of twins and stacking faults are one of the main reasons for the uneven plastic deformation of the alloy.The analysis shows that the Young’s modulus and yield stress of the HEA decrease linearly with the increase of Al concentration.The HEA have strong temperature effect.The lower the temperature,the smaller the Al concentration,and the greater the decrease in Young’s modulus and yield stress.