Grain Boundary Property Determination through Measurement of Triple Junction Geometry and Crystallography

Microstructure controls the properties of most useful materials. Thus an ability to control microstructure through the processing of materials is a key to optimization of materials performance. Most materials are polycrystalline and their grain structure is a very important aspect of their microstructure. Thanks to their complexity there is a great variety of grain boundary types even in relatively isotropic materials such as the cubic metals. Simply describing the crystallography requires five (macroscopic) parameters (e.g. disorientation and inclination). Evidently, acquiring a knowledge of the variation of properties such as energy and mobility as a function of grain boundary type would be of great value in predicting properties and optimizing processing. This paper outlines the methods being employed to extract such properties from the geometry and crystallography of triple junctions between grain boundaries.