Quantitative evaluation of plastic strain gradients generated during orthogonal cutting of an aluminum alloy

Deformation microstructures developed in the material ahead of tool tip in the 6061 Al alloy samples subjected to an orthogonal cutting process were investigated. Samples of hot extruded 6061 Al that contained inherent microstructural markers in the form of extrusion lines were cut at a low speed. Metallographic sections were examined to measure local displacement fields in the deformed material. This information was used to estimate local variations in shear angles. A method to determine the plastic strain gradients in the material ahead of the tool tip has been established and the distribution of equivalent strains has been summarized in a diagram constructed from the measured deformation angles.