New method to characterise grain boundary plane orientations based on EBSD orientation microscopy for serial sectioned surfaces

Abstract

A new 'elementary facet' method has been developed to measure grain boundary (GB) plane orientations using three-dimensional electron backscattered diffraction on serial sectioned surfaces in a sample. The method defines different types of elementary facets in an orthogonal coordinate system in the sample. These elementary facets are used to pave GBs. For a flat GB, its projected areas on the orthogonal coordinate planes in the sample are obtained from the numbers of different facets paved in the GB. From the projected areas of the GB plane in the three coordinate planes, the GB plane normal is derived. For uneven GBs, a convolution method has been developed to obtain the GB plane orientations at different GB locations. In essence, this new method measures the GB orientations at every elementary facet that is used to pave the GBs in the sample. Together with the measured crystal orientations of different grains, the GB five parameters at all facets can be obtained readily. The distribution of GB five parameters for the whole GB population in a sample can be derived from the collection of properties of individual GB facets in the sample.