Evaluation of Strength of Heterometal Interface by Atomic Elastic Stiffness

Abstract

Molecular dynamics simulations are performed on a laminate structure of several bimetal interface such as Ni/Fe, Al/Fe and Ni/Al, and the deformation/fracture behavior are discussed with the eigenvalue for the solution of B^a_ij Δε_j = η^aΔε_i, where B^a_ij = Δσ_i^a/Δε_j is the atomic elastic stiffness. Slip deformation occurs from the Ni(001)/Fe(001) interface when the 1st eigenvalue ¯η^a(1) of the interface, or the averaged η^a(1) of atoms on the interface, becomes negative under tension. Both the Al(001)/Fe(001) and Ni(001)/Al(001) laminates shows amorphization in Al phase when all the ¯η^a(1) in Al phase becomes negative, or unstable condition of whole Al phase.