Micromachining Imposed Subsurface Plastic Deformation in Single-Crystal Aluminum

Abstract

In this work, we analyzed the nature and extent of deformation beneath the machined surface during orthogonal micromachining of single-crystal aluminum. We micromachined six different crystallographic orientations of a sample with [111] zone-axis and analyzed the sub-surface texture and resulting misorientations. The results indicate that the changes in crystallographic orientation induces variations in the depth of deformation, the degree of grain refinement and the lattice rotations. We observed up to 50% lattice rotations, shear bands varying from 55o to 60o from the direction of machining, and highly entangled dislocations, which confirmed the presence of strain hardening.