Experimental analysis and computational modeling of pile-up formation in nanoindentation

We present the results of an experimental investigation and atomistic simulation on the effects of orientation of indentation planes on the formation of pile-ups using nanoindenter for FCC and BCC Nickel, Copper, and Iron. Molecular dynamics (MD) method is used to simulate nanoindentation on FCC Nickel to understand the relationship between material pile-up and microscale dislocation activities. It is found that predicted pile-up patterns are dependent on surface orientation. The pile-up patterns are closely related to dislocation nucleation and motion on different slip systems that are activated by multi-axial stress mechanisms in indentation