Elastic properties of TiC and TiN crystals in high temperature range

The elastic properties of crystals at high temperature are of significant interest as they affect the mechanical stability and performance of materials at elevated temperatures. In present study a theory for evaluating the temperature variation of second third and fourth order elastic constants for face centred cubic crystal structure solids is used on the basis of Coulomb and Born-Mayer potential using nearest-neighbour distance and hardness parameter. The theory is first applied to get the second order elastic constants (SOECs) and third order elastic contants (TOECs) for TiC and TiN crystals at different temperatures up to 500 K. In addition, the elastic constants thus obtained are used to evaluate the first order pressure derivatives (FOPDs) SOECs and TOECs. The elastic properties of these crystals at high temperature are of significant interest and are related to other important material properties such as thermal expansion, thermal conductivity, phase transformations, creep behaviour, oxidation resistance, and high-temperature strength. The results obtained show that the second order elastic constants and third order elastic constants of TiC are highest, so mechanical properties of TiC will be better than TiN, which makes it stiffer and more resistant to deformation under an applied load. These properties make TiC a popular material for cutting tools, wearresistant coatings, and other high-performance applications.