Pressure-induced effects on elastic and mechanical properties of TiC and TiN: A DFT study

Pressure-induced effects on elastic, structural phase transition and mechanical properties of TiC and TiN are studied under high pressures from first-principle calculations. Calculated lattice parameters, elastic constants and theoretical Vickers hardness are in excellent agreement with available experimental and theoretical results. The transition pressure from NaCl to CsCl phase is determined with values of 5.695 Mbar for TiC and 3.482 Mbar for TiN. Pressure-induced effects on mechanical properties of NaCl-type TiC and TiN show that the Vickers hardness increases first, to a maximum value 43.65 and 27.48 GPa at the pressure of 2.1 and 0.9 Mbar for NaCl-type TiC and TiN, respectively, and then decreases with increasing pressure