The effect of substitutional alloying of transition elements on elastic properties of B2 NiAl has been studied using first-principles electronic-structure calculations by means of the exact muffin-tin orbitals method in conjunction with the coherent potential approximation [1]. We investigated the site preference of ternary additions at T = 0 K and created a database of ab initio elastic constants C11, C12, and C44, shear moduli G, bulk moduli B, Young moduli E, Pugh ratio G/B, and Cauchy pressure PC. Our calculations have shown that the addition of W, V, Re, and Ti should improve the ductility of B2 NiAl without significant changes in the macroscopic elastic moduli. Therefore, in this study we have carried out a detailed investigation of the effect of tungsten content on the elastic properties, the density of states and Fermi surface topology in NiAl-W alloys.
To verify theoretical predictions experimentally an analysis of adiabatic combustion temperature in the ternary system was performed depending on the content of alloying metal. As a result two schemes of synthesis of alloyed materials have been chosen: 1) the mechanical structuring of the three components in a planetary ball mill to create composite particles containing all three components with the subsequent self-propagating combustion synthesis and 2) the synthesis of unstructured mixture in thermal explosion mode.
[1] A. V. Ponomareva, E. I. Isaev, Yu. Kh. Vekilov and I. A. Abrikosov, Phys. Rev. B 85, 144117 (2012)