Three-Dimensional Architecture of Engineering Multiphase Metals

The thermomechanical properties of multiphase metals are determined by a combination of the properties of the microstructural phases and the internal architecture formed by them. The latter must be described using three-dimensional techniques in cases where the phases are distributed nonuniformly, have complex morphologies, form interconnected structures, and present contiguity between those structures. Furthermore, all these morphological aspects may change during service exposure. One of these techniques is X-ray tomography, which has experienced an increased interest from materials scientists during the past decade owing to the advances in spatial and time resolution to reveal nondestructively the internal structure of materials. The present review summarizes the main features of this technique in regard to its capabilities to image metal-based engineering materials three dimensionally. Special emphasis is put on the contributions of X-ray tomography to understand the relationships between architecture and thermomechanical properties with specific examples for lightweight metals, cast iron, steel, and metal matrix composites.