Metal Based Composites With Metastable/Amorphous Reinforcements

Abstract

Advent of metal matrix composites (MMCs) has revolutionized the development of materials over almost last four decades. Metal matrix composites have the capability to exhibit many enhanced targeted properties when compared to traditional engineering materials provided their microstructural constituents are judiciously integrated. This article addresses the processing methods and properties of lightweight MMCs containing metastable/amorphous reinforcements. Traditionally, strong and hard ceramic particles reinforcements were commonly used to develop MMCs. Such composites, many times exhibited limited improvements in mechanical properties due the early onset of particle-based damage mechanisms such as particle breakage (at micron length scale), interfacial de-cohesion and undesirable reaction at metallic matrix- ceramic interface. To overcome the limitations (such as low ductility) of MMCs (with conventional ceramic reinforcements), amorphous alloys are currently recognized as alternative replacements for the conventional reinforcements. When compared to ceramic reinforcements, the inclusion of amorphous metallic alloys minimizes particle based damage mechanisms leading to enhanced realization of properties of end materials. In view of the promise of amorphous reinforcements, an overview of the existing literature regarding the processing and properties of Al and Mg-matrix composites having metastable/amorphous reinforcement is detailed in this present article.