Mechanical milling-induced deformation twinning in Fcc materials with high stacking fault energy

The high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) studies, as well as conventional transmission electron microscopy (TEM) observations, indicated the presence of a large number of highly twinned grains. The twinned structure was thought to be responsible for the higher creep resistance in the nanocrystalline Cu and Pd, because twin boundaries were poor paths for vacancy diffusion and resist grain boundary sliding. As such, the presence of deformations twins in several milled fcc metals and alloys with high stacking fault energy was observed using conventional TEM and HRTEM, and the density of twins was analyzed using X-ray diffraction (XRD).