Effects of Fe atoms on hardening of a nickel matrix: Nanoindentation experiments and atom-scale numerical modeling

Significant hardening effect due to Fe concentrations in Ni-based alloys with face-centered-cubic structure has been studied by using a combined experimental and atomistic-based computational approach via nanoindentation tests. The obtained load–displacement data for the [0 0 1] crystal orientation reached qualitative good agreement molecular dynamics simulations results, leading strong evidence that main strengthening factors are associated sluggish dislocation diffusion, reduced defect sizes nucleation of tetrahedral stacking faults. Here, interstitial type prismatic loops mainly formed ??1 1 2? Shockley dislocations nucleated during loading process, where their interaction leads formation pyramidal shaped fault which created ??1 0? Hirth lines. Observing both types defects coexisting same plastic deformation zone approaches. Reported mechanical data, measured experimentally interpreted numerically, also accordance microstructural SEM TEM investigations.