Effects of temperature and pressure on the mechanical and thermodynamic properties of high-boride WB4 from first-principles predictions

Abstract

Tungsten borides with high boron content are widely used in high temperature and high pressure conditions. In this work, the first-principles calculations were employed to investigate the influence of pressure and temperature on the structure, mechanical properties and thermodynamic properties of hp10-WB4. The results show that hp10-WB4 is dynamically and thermodynamically stable over a range of temperatures (0–800 K) and pressures (0–35 GPa). In general, the elastic constants and modulus are improved at the appropriate pressure state. The single crystal tensile simulations in the ground state show that hp10-WB4 has good strength. And the lattice parameters, crystal structure stability, electronic properties, heat capacity, thermal expansion coefficient α, Debye temperature θD and Grüneisen parameter γ are also investigated at 0–35 GPa pressure and 0–800 K temperature. The thermal expansion coefficient is sensitive to temperature and pressure. The Debye temperature and Grüneisen parameters show the opposite trend, and the effect of temperature and pressure on them is slight.