Wang Yueyi, Liu Hongxi, Hao Xuanhong, Yang Chen, Liu Yaxia, Chen Lin, Zhang Xiaowei
The Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming 650093, People's Republic of China.
School of Materials Science and Engineering, Baise University, Baise 533000, People's Republic of China.
J Phys Condens Matter. 2024 Sep 5;36(48). doi: 10.1088/1361-648X/ad7437.
This work uses first-principles calculations to investigate the phase stability, thermophysical and mechanical properties of refractory high entropy alloys (RHEAs) at finite temperatures. On the basis of plane wave quasi-potential and density functional theory, construct the structure model of a solid solution. The TiMoNbX (X = Cr, Ta, Cr and Ta) RHEAs have been determined to preserve a single body-centered cubic solid solution structure by calculations and the equilibrium lattice parameters and elastic modulus are consistent with experimental data obtained by laser cladding, which is combined with TC4 (Ti-6Al-4V) substrate. Using the quasi-harmonic Debye-Grüneisen model, the thermophysical characteristics of three RHEAs are investigated. The Voigt-Reuss-Hill scheme is used for calculating the Young's modulus (), bulk modulus (), shear modulus (), and Poisson's ratio (), which indicates that all three RHEAs are ductile materials. Additionally, the modulus and hardness of materials decrease as temperature rises, whereas the properties of TiMoNbX RHEAs are predicted, as the nanoindentation hardness values at room temperature are comparable to, and slightly higher than the calculated values.
这项工作采用第一性原理计算方法，研究了难熔高熵合金（RHEAs）在有限温度下的相稳定性、热物理性能和力学性能。基于平面波赝势和密度泛函理论，构建了固溶体结构模型。通过计算确定了TiMoNbX（X = Cr、Ta、Cr和Ta）RHEAs保持单一的体心立方固溶体结构，其平衡晶格参数和弹性模量与通过激光熔覆获得的实验数据一致，该实验是与TC4（Ti-6Al-4V）基体相结合进行的。使用准谐德拜-格林爱森模型研究了三种RHEAs的热物理特性。采用Voigt-Reuss-Hill方法计算杨氏模量（）、体模量（）、剪切模量（）和泊松比（），结果表明所有三种RHEAs都是韧性材料。此外，材料的模量和硬度随温度升高而降低，而TiMoNbX RHEAs的性能得到了预测，因为其室温下的纳米压痕硬度值与计算值相当且略高于计算值。
