Texture analysis of a recrystallized quartzite using electron diffraction in the scanning electron microscope

The microstructure and crystallographic preferred orientation (texture) of a recrystallized quartzite from the Bergell Alps was quantitatively investigated using automated indexing of electron backscattered patterns (EBSP). The results are displayed in orientation maps of the microstructure and orientation as well as misorientation distribution functions. The orientation distribution function derived from EBSP compares excellently with texture data derived from independent neutron diffraction experiments. The misorientation distribution function of next neighbors reveals strong maxima for small angle grain boundaries (subgrain boundaries) and the Dauphiné twin correlation. The Dauphiné twins, which are generally not detectable optically, are not correlated with specific maxima in the orientation distribution function. Their origin and their role during recrystallization is discussed. During recrystallization no other preferred high angle misorientations developed. The frequent occurrence of small angle grain boundaries indicates progressive subgrain rotation as a recrystallization mechanism.