Effect of stress-induced anisotropy and porosity on elastic properties of polycrystals

Abstract

Recent ultrasonic measurements performed on hot-pressed polycrystalline materials as a function of pressure and temperature simultaneously indicate that the interiors of the specimens may not be strain free. Residual strain arising from the fabrication process produces an anisotropic effect separate from any anisotropy that may arise simply from relative grain orientations that may or may not be randomized. Internal strain has a significant effect on measurements of the bulk modulus and particularly of its pressure derivative. The effect of residual porosity and permeability on the pressure derivative of the bulk modulus is also examined.