Orientation Imaging Microscopy Investigation of the Compression Deformation of a [011] Ta Single Crystal

Abstract

High-purity tantalum single crystal cylinders oriented with [011] parallel to the cylinder axis were deformed 10, 20, and 30 percent in compression. The samples took on an ellipsoidal shape during testing, elongated along the [100] direction with almost no dimensional change along [011]. Two orthogonal sectioning planes were selected for characterization using Orientation Imaging Microscopy (OIM): one in the plane containing [100] and [011] (longitudinal) and the other in the plane containing [011] and [011] (transverse). OIM revealed patterns of alternating crystal rotations that develop as a function of strain and exhibit evolving length scales. The spacing and magnitude of these alternating misorientations increase in number density and decrease in spacing with increasing strain.