First principles investigation of the Structural, Mechanical, Electronic Properties and Debye temperature of W-Co alloys

摘要

In this paper, we have investigated the crystal structure, mechanical properties, electronic properties and Debye temperature of W-Co alloy according to the first principles method. The configurations investigated are W15Co1, W14Co2, W12Co4 and W8Co8 alloys, respectively. The results show that W-Co alloy still maintains a cubic lattice, and the lattice constant is lower than that of pure W. The formation energy analysis shows that the thermodynamic stability of W-Co alloy decreases with the increasing Co concentration. According to the mechanical stability criterion, it is concluded that W8Co8 alloy is mechanically unstable. Based on the elastic constant and other mechanical parameters analysis, the mechanical strength of W15Co1, W14Co2 and W12Co4 alloys is weaker than that of pure W. However, the B/G ratio and Poisson's ratio of W15Co1, W14Co2 and W12Co4 alloys are greater than that of pure W, indicating that Doping Co can improve the ductility of pure tungsten. Besides, the anisotropy, melting point and hardness, and Debye temperature of W-Co alloy is also evaluated.