Studies on tribological and machinability characteristics of aluminium mmc reinforced with yttria through friction stir processing

Abstract

Combined strength and stiffness with low density is the major drawback of traditional monolithic materials. As Metal Matrix Composites (MMC s) are proficient to conquer these deficiencies, they are gaining interest globally. Composites are manufactured for a variety of purposes with the intention of meeting the growing engineering requirements, where greater performance with low specific weight is demanded. Recognition of these light metals in particular application is still not easy, even though modernization in technology have simplified the development of MMC. The core causes for this are poor process steadiness and consistency, improper manufacturing and processing methodologies and high principal investments because of why the MMCs are still trailing in the era of modern materials . A composite material is a combination of two or more materials in which a hard reinforcement is usually surrounded by the soft matrix material. Generally composites can be classified based on based on base and reinforcement material. It is classified as Polymer Matrix Composites (PMC s), Metal Matrix Composites (MMC s) and Ceramic Matrix Composites (CMC s) according to type of base material used. Similarly, it is classified as fibre reinforced composites, laminar composites and particulate composites according to type of reinforcement material used for composite fabrication. The composite which uses metal as matrix material is called as Metal Matrix Composites. At present, surface composites (reinforced only on matrix surface) are commonly preferred over bulk composites (reinforced throughout the matrix) as modern applications expect more surface properties (eg.- wear) than the bulk properties (eg.- strength) Even though these MMCs are exposes improved properties than that of monolithic materials, attaining uniform distribution of reinforcements in matrix with flawless microstructure is one of the major discomforts in surface MMC s. This setback can be overcome by appropriate MMC processing route selection. The usual surface processing methodologies such as hard facing coating and surface re-melting are mostly applicable to modify the microstructure to conquer the aforesaid difficulties. On the other hand, compensation in hardness and reduced wear resistivity are inevitable while using these traditional techniques for Aluminium MMC s development. Friction Stir Processing (FSP), the advanced solid state surface processing method can be utilized to overcome these problems of traditional technique newline