On the Development of New Scalar Measures of Heterogeneity

One of the key advantages of measuring textures by electron backscatter diffraction (EBSD) is the ability to obtain spatially specific orientation data. This allows the spatial distribution of texture or microtexture to be characterized. The local variation in texture is often apparent in maps generated by mapping various orientation parameters on to a color scale. While orientation maps provide a visual indicator of local texture variations, a quantitative description is needed for comparing the heterogeneity between different materials. This paper reports on two scalar parameters developed for characterizing heterogeneity - one parameter for characterizing the severity of texture gradients and the other for quantifying the degree of texture banding. The practical application of these measures to a tantalum sample is presented. Variations in the values measured for different scan densities were observed. Thus, a procedural resolution to mitigate these variations arising from the scanning conditions is proposed.