DEVELOPMENT OF LIGHT WEIGHT ALUMINIUM METAL MATRIX COMPOSITE BY STIR CASTING PROCESS

Abstract

In recent years, the developments of metal matrix composite (MMCs) have been receiving worldwide attention on account of their superior strength and stiffness. They also have high wear resistance and creep resistance in comparison to their corresponding wrought alloys. The existing process to fabricate, characterize and machine this special material needs improvement. Although, some attempts have been made to machine these materials but no suggestion has been made so far about the optimum value of cutting parameters for a particular type of MMC. Optimum value of cutting parameters will be different for different MMCs. Some categories of these MMC find applications in aircraft and space industries, where precise machining is most important. Hence, there is a need to develop a process for precise, energy efficient and cost effective machining. So that Aluminium composites for light weight applications can be fabricated cost effectively. So this study is aimed at low cost fabrication of Aluminium metal matrix composite with Boron carbide (B4C) as dispersed phase and AA7075 as matrix phase which can be used in various light weight applications by using ‘Stir Casting’ method. The developed composite shows improved tensile and yield strength along with increase in vicker’s hardness. The microstructure studies have also been carried out which uniform distribution of reinforcement particles, phases made after development of composite and also the reduction in grain size. The wear test was also done which revealed favorable results. Further optimization of machining results has been done for studying the effect of speed, feed and depth of cut. The results have been compared with the results of as-casted AA7075.