ANALYSIS OF INTERFACE DAMAGE HETEROGENEITY IN POLYCRYSTALLINE MATERIALS

The Interface Damage Function (IDF) defining fractional damage of intercrystalline interfaces in polycrystalline materials, with functional dependence upon lattice misorientation and boundary normal orientation, is described. A method of section analysis to calculate the IDF is derived; it is shown to depend upon a convolution with the Intercrystalline Structure Distribution Function (ISDF) which has been defined in previous work. This convolution is expressed in a double integral equation which is solved by the Fourier method. Application of the theory to cavitation damaged OFHC copper is described. Illustrated is a rich structure of the IDF which illuminates the mechanisms of heterogeneity in creep damage. Random high-angle boundaries are found to be remarkably damage resistant, while some special boundaries are preferentially damaged. A varied response of the damage to shear and normal components of the applied stress is also observed. © 1990.