第一性原理计算Fe元素含量对高熵合金AlCoCrCuFe_xNi的影响

First-principle Studies of AlCoCrCuFe_xNi High Entropy Alloys with the Different Mole Fractions of Fe

采用第一性原理密度泛函理论,结合平面波赝势和广义梯度近似(GGA),用虚拟晶体近似(VCA)的方法建立晶体结构模型,计算了高熵合金AlCoCrCuFexNi的结构性能、弹性性能及生成热。计算结果表明,高熵合金AlCoCrCuFexNi的密度随着Fe元素摩尔含量的增大而增大,晶格常数在Fe元素摩尔含量为1时最小。Fe元素的摩尔含量并不能改变高熵合金AlCoCrCuFexNi的力学稳定性。生成热随着Fe元素摩尔含量的增大而减小,但是皆为负值,表明高熵合金在热力学条件下是稳定的。

The structural properties, elastic properties, and the heat of formation for the high entropy alloys （HEAs） AlCoCrCuFexNi were studied by density functional theory and plane-wave pseudopotental technique with generalized gradient approximation （GGA）, the crystal structure was built with the Virtual Crystal Approximation （VCA）. The calculated results indicate that the mass density of HEA A1CoCrCuFe^Ni increases with the increasing mole fraction of Fe, the lattice parameter is the largest when the mole fraction of Fe is 1. The mechanical stability of the HEA AlCoCrCuFexNi is nothing to do with the,mole fraction of Fe. The heat of formation decreases with the increasing mole fraction of Fe, but the HEAs AlCoCrCuFexNi are thermodynamically stable due to their negative heats of formation.