Ab Initio Simulation of Structure and Properties in Ni-Based Superalloys: Haynes282 and Inconel740

The electronic structure, interatomic bonding, and mechanical properties of two supercell models of Ni-based superalloys are calculated using ab initio density functional theory methods. The alloys, Haynes282 and Inconel740, are face-centered cubic lattices with 864 atoms and eleven elements. These multi-component alloys have very complex electronic structure, bonding and partial-charge distributions depending on the composition and strength of the local bonding environment. We employ the novel concept of total bond order density (TBOD) and its partial components (PBOD) to ascertain the internal cohesion that controls the intricate balance between the propensity of metallic bonding between Ni, Cr and Co, and the strong bonds with C and Al. We find Inconel740 has slightly stronger mechanical properties than Haynes282. Both Inconel740 and Haynes282 show ductile natures based on Poisson's ratio. Poisson's ratio shows marginal correlation with the TBOD. Comparison with more conventional high entropy alloys with equal components are discussed.

Automated summary

The electronic structure, interatomic bonding, and mechanical properties of two supercell models of Ni-based superalloys, Haynes282 and Inconel740, were calculated using ab initio density functional theory methods. The alloys exhibited complex electronic structure, bonding, and partial-charge distributions, depending on the composition and strength of the local bonding environment. The total bond order density (TBOD) and its partial components (PBOD) were used to determine the internal cohesion and balance between metallic and strong bonds. Inconel740 showed slightly stronger mechanical properties than Haynes282 and both alloys exhibited ductile natures based on Poisson's ratio. The correlation between Poisson's ratio and TBOD was marginal. A comparison with conventional high entropy alloys was discussed.