Theoretical study of AlN mechanical behaviour under high pressure regime

Abstract

Aluminum nitride (AlN) is a very important industrial and technological material due to its properties, e.g. high melting point, thermal conductivity, electrical resistivity, mechanical strength, and corrosion resistance. This work represents detailed study of mechanical and elastic properties of AlN structures under compression. Theoretical modeling has been performed using quantum mechanical calculations and computed values were compared with the experimental results when available. Structural properties, volume change and strain (dilatation) under high pressure has been investigated for various AlN phases. Elastic constants Cij for wurtzite, sphalerite and rock salt structure were calculated under pressure. Important mechanical properties were investigated; bulk modulus B, shear modulus K, Young's modulus E, Vickers hardness Hv, anisotropy, stiffness, Poisson's ratio, brittleness/ductility, in order to investigate influence of pressure on wurtzite, sphalerite and rock salt based AlN materials. Detailed analysis of anisotropic mechanical properties under compression has been performed, as well as relationship between B, K, E and Hv, in order to offer novel technological and industrial applications of AlN. © 2019 Elsevier Ltd