First-principles calculations of mechanical properties of TiZrNbTaMo series biological refractory high-entropy alloys

TiZrNbTaMo series refractory high-entropy alloys (RHEAs) exhibit significant potential in biomedical implant applications due to their outstanding mechanical properties and biocompatibility. Based on first-principles calculations combined with the virtual crystal approximation method, the influence of various element contents on the mechanical properties of TiZrNbTaMo series RHEAs has been investigated in this study. By calculating the physical parameters such as elastic properties, hardness, yield strength, and dislocation energy factor of TiZrNbTaMo RHEA with various element contents, it is found that the addition of Nb element can increase the Cauchy pressure value of the alloy, thereby improving the metallic properties of atomic bonds. Increasing the Ta and Mo content significantly boosts the Young's modulus and hardness of the alloy, while also enhancing its resistance to volume and shear deformation. And among, TiZrNbTa _0.5 Mo RHEA exhibits the largest dislocation width, lower stacking fault energy, and is more susceptible to twinning deformation than other RHEAs. However, increasing Ti and Zr content enlarges the dislocation width of the alloy, making it more prone to slip. To sum up, this study provides a theoretical reference for further investigation into the mechanical property changes of TiZrNbTaMo series RHEAs.