Al0.1CoCrFeNi高熵合金力学性能的分子动力学研究

Mechanical Properties of Al0.1CoCrFeNi High Entropy Alloy Based on Molecular Dynamics Study

摘要:

通过分子动力学方法研究了Al_0.1CoCrFeNi单晶高熵合金在室温（300 K）下沿轴向拉伸后的组织和力学性能变化。通过改变模拟应变速率和温度，分析了单晶高熵合金的拉伸性能；通过模拟室温拉伸实验，研究了含表面小裂纹单晶的显微组织和抗拉伸性能。结果表明，当应变速率在一定范围内时，抗拉伸强度随应变速率增大而增大；当应变速率为10¹⁰ s^-1时，杨氏模量和抗拉伸强度随温度降低而增大。表面有贯穿小裂纹的单晶高熵合金在拉伸一段时间后出现颈缩现象，随着大量滑移位错的快速发展，裂纹尖端出现应力集中，导致快速断裂。

Abstract:

The microstructure and mechanical properties of Al_0.1CoCrFeNi single crystal high entropy alloy (HEA) under axial tensile loading at room temperature (300 K) were investigated by molecular dynamics method. The tensile properties of the single crystal HEA were analyzed by changing the simulated strain rate and temperature. The microstructure and tensile properties of the single crystal HEA with small surface cracks were studied by simulating tensile experiments at room temperature. Results demonstrate that the tensile strength is increased with increasing the strain rate in a certain range; the Young's modulus and tensile strength are increased with decreasing the temperature at strain rate of 10¹⁰ s^-1. The single crystal HEA with small through cracks on surface presents a necking phenomenon after stretching for a period, and the stress concentration occurs at the crack tip along with the rapid development of a large number of slip dislocations, resulting in the rapid fracture.