Effect of alloying element Ta on elastic properties and electronic structure of γ'-Ni₃Al phase

The elastic properties and electronic structure of Ta-doped γ'-Ni₃Al Phase have been investigated by the pseudo-potential plane wave (PP-PW) method within density functional theory. The calculated results show that Ta can effectively strengthen the elastic properties of Ni₃Al alloys, which makes the Young's modulus increase by 12.86%. The Ni₃(Al, Ta) intermetallic compound behaves in ductile, but is more brittle than Ni₃Al in nature. Using a sum of overlap populations of all bonds in the supercell, the covalent bonding of intermetallic compounds was evaluated quantitatively. It is found that Ta can increase the covalent bonding of γ'-Ni₃Al. The bond characters were also analyzed using valence charge densities and total density of states, and the results indicate the chemical bonds in γ'-Ni₃(Al, Ta) can be classified as a mixture of directional covalent and metallic characteristic.