On anisotropy of indentation induced piling-up by using optical microstrain measurement

[[abstract]]Full strain field measurement is used to study indentation-induced plastic patterns around a spherical indenter. An optical strain measurement system incorporates a digital image correlation (DIC) method to determine displacement fields from two images acquired before and after deformation, and the full strain field is obtained from the displacement field. During indentation, the 99.999% pure aluminum specimens of a single crystal reveal anisotropy deformation behavior. The phenomenon of piling-up and residual impression is successfully detected by analyzing the sign of the strain in the position of the indentation and around the indenter, respectively