First-principles study of the mechanical and thermodynamic properties of Al4W, Al5W and Al12W under pressure

Abstract The mechanical and thermodynamic properties of Al4W, Al5W and Al12W under pressure have been studied using the first-principles calculation. The lattice constants and volume ratio decreased with increasing pressure. The calculated values of the elastic constants showed that Al4W, Al5W and Al12W were mechanically stable under pressure of 0–20 GPa. The pressure improved the resistance to deformation. According to the results of B/G ratio and the Cauchy pressure (C12–C44) calculations, Al4W and Al12W changed from brittle to ductile behavior when the pressure was above 15 GPa. The microhardness of Al4W (14.26 GPa) was larger than that of Al12W (10.39 GPa) under 0 GPa, which was in accordance with the experimental findings. The temperature and pressure had opposite effects on the heat capacity at constant volume (Cv). The ability to release or store heat for Al12W was greater than that for Al4W and Al5W.