Ti_xNbMoTaW 系高熵合金性能的第一性原理计算

NbMoTaW alloy is one of the most widely studied refractory high entropy alloys. It has the excellent properties of high entropy alloy,high strength,high hardness and wear resistance,but its toughness is poor,which greatly affects its application in engineering. In this study,different proportions of Ti elements were added into NbMoTaW alloy to improve the toughness of the alloy. The phase structure of TixNbMoTaW was determined to be solid solution phase by calculating the phase formation parameters. The crystal lattice constant,formation energy and enthalpy change of the alloy were calculated by the first-principles method based on density functional theory to analyze the structural stability of the alloy. By calculating the elastic constants,elastic modulus,B / G,Poisson ratio ν ,Cauchy pressure C₁₂ -C₄₄ and other parameters of the alloys with different Ti content,the elastic properties of the alloys were studied. Finally,the electron state density analysis shows that the bonding covalence of the alloy system decreases and the metal bond strengthens. The results of elastic properties and state density show that adding Ti can improve the toughness of the alloy. This study can provide some theoretical guidance and design ideas for designing and improving the properties of refractory high entropy alloys.