第一原理计算高熵合金CoCrFeNi的弹性性质

First principles calculation of elastic properties of high-entropy alloy CoCrFeNi

CoCrFeNi是一种简单的四元高熵合金,具有FCC结构。本文用单胞模型,并通过第一原理密度泛函方法计算了四元高熵合金CoCrFeNi的晶格常数及弹性性质。计算结果与实验结果对比发现,晶格常数计算值与实验符合得较好,而弹性性质却和实验有一定的差异。基于对高熵合金的认识,从实验和理论两个角度分析了差异产生的原因,并预测CoCrFeNi脆性大,延展性较差。为高熵合金的理论研究提供了一种新的方法。

CoCrFeNi is a simple four element high-entropy alloy with FCC structure.In this paper,a single cell is used to represent the model,and the lattice constant and the elastic properties of the four element high entropy alloy CoCrFeNi are calculated by the first principle density functional method.The results are compared with the experimental results.It is found that the lattice constant theory agrees well with the experimental results,but the elastic properties have some errors with the experiment.Based on the understanding of materials,the causes of errors were analyzed.The results show that the CoCrFeNi has high brittleness and poor ductility.This work provides a new method for the theoretical study of the elastic properties of high-entropy alloys.