EFFECT OF GRAIN SIZE AND PRESSURE ON TWINNING AND MICROBANDING IN OBLIQUE SHOCK LOAKING OF COPPER RODS

摘要

High-purity copper rods in a range of grain sizes-29 μm, 141μm and 375μm-were shock loaded in an obliuqe, cylindrical shock fixture which simultaneously and linearly strained the rods from zero to 5/100 at peak pressures calculated to range from 11 to 30 Gpa at the top and bottom of the rods, respectively. These pressures correspond to the minimum and maximum shock deformation. Light metallography and transmission electron microscopy revealed that the density of deformation twins was measurably and observable increased with both increasing grain size and deformation (pressure).