The Ni3Al/Ni Interfacial Contribution to the Indentation Size Effect of Ni-Based Single-Crystal Superalloys

Hardness decreases as indentation depth increases at both the nano- and micro-meter scales. By incorporating interfacial contributions, the indentation size effect can provide valuable information on the deformation behaviors of Ni-based single-crystal superalloys. In this paper, through experimental studies and atomistic simulations, we examine the indentation size effect and mechanical behaviors of Ni-based single-crystal superalloys. The results demonstrate that the indentation size effect, in conjunction with the Ni3Al/Ni interfacial network, is effectively captured by a modified Nix–Gao model. Molecular dynamics simulations further reveal the underlying atomistic mechanisms and microstructural evolution during nanoindentation. These findings provide new insights into the deformation behavior of Ni-based single-crystal superalloys and support their wide applications in the aerospace industry.