HETEROGENEITY OF INTERGRANULAR DAMAGE IN COPPER CREPT IN PLANE-STRAIN TENSION

An interface damage function (IDF), which statistically describes the area fraction of interface damage as a function of up to eight parameters defining crystallite interfaces, was determined for commercial-purity copper specimens crept in plane-strain tension. The IDF was determined from stereological parameters measured on plane sections cut through damaged specimens. The eight-dimensional space of the function was investigated by analyzing two-dimensional projections of the complete domain. Certain 'special" interfaces were observed to damage preferentially. A low planar density of atoms near crystallite interfaces apparently increased the propensity for the occurrence of damage. Other microstructural mechanisms contributing to the observed heterogeneous distribution of damage are also considered.