ORIENTATION IMAGING MICROSCOPY - EMERGING AND FUTURE APPLICATIONS

Orientation imaging microscopy (OIM), which images the microstructure using the electron backscattered diffraction probe, has proven to be a powerful tool for the study of polycrystalline materials. OIM's chief strength lies in its ability to couple the morphological aspects of m icrostructure, with lattice orientation. With spatial and angular reso lution of at least 100 nm and 1 degrees, OIM is ideally suited to inve stigations at the mesoscale. In this paper three examples are describe d which illustrate emerging and future applications of OIM to importan t problems in materials science at the mesoscale. The first example is the use of higher-order point statistics to obtain improved bounds on structure-insensitive properties. It is emphasized that the approach may be used, not only to enhance material properties, but also to cont rol their variability. The second example is an emerging analysis to m ap the relationships between the character (type) of grain boundaries and their intrinsic properties. The main idea is illustrated for mappi ngs linking character and excess free energy. The third example focuse s on the ability of OIM to measure lattice curvature, and to thereby o btain information about the geometrically necessary dislocation conten t of the microstructure. This example is illustrated by analysis to ex tract the dislocation density tenser.