Magnesium based surface metal matrix composites by friction stir processing

Surface metal matrix composites (MMCs) are a group of modern engineered materials where the surface of the material is modified by dispersing secondary phase in the form of particles or fibers and the core of the material experience no change in chemical composition and structure. The potential applications of the surface MMCs can be found in automotive, aerospace, biomedical and power industries. Recently, friction stir processing (FSP) technique has been gaining wide popularity in producing surface composites in solid state itself. Magnesium and its alloys being difficult to process metals also have been successfully processed by FSP to fabricate surface MMCs. The aim of the present paper is to provide a comprehensive summary of state-of-the-art in fabricating magnesium based composites by FSP. Influence of the secondary phase particles and grain refinement resulted from FSP on the properties of these composites is also discussed