Investigation OF a356sicgr hybrid composites fabricated by stir cum squeeze casting process

Abstract

Light weight without compromising strength for long dynamic life components requirement is the main challenges faced by automakers all over the world. On the contrary, industrialists are demanding manufacturing comforts due to its demand and quality. To face these challenges, automakers are driving towards aluminium hybrid metal matrix composites fabricated via squeeze casting technique as a solution to overcome heavy weight alternative parts. An overture work appraisal of A356 assorted as a matrix material with Silicon Carbide (SiC) and Graphite (Gr) as a hybrid blend is a modern group of hybrid composites that have the ability to unravel demands of advanced engineering applications especially where high strength is required and frictional areas. The proper selection of casting process shows better properties, so that squeeze casting technique was introduced to remove cast pores to form high strength hybrid composites. The experiments were planned to fabricate an A356 as a matrix material with 3, 6, 9,12wt% of SiC and 3 wt% of Gr as reinforcements were added with the matrix material to cast the hybrid composites at optimal process variable conditions using squeeze casting technique. The reinforcements preheated to a temperature of 300and#730;C, stirred at constant speed of 400 rpm for five minutes, die cavity maintained at 225and#730;C through the preheated passage to bottom pouring furnace and a applied squeeze pressure of 140Mpa respectively to produce sound castings. Further, for T6 heat treatment, a cast samples are dipped into a solution and solution is gradually raised to a temperature of 540and#730;C for continuous 4 hours. After 4 hours, the samples are taken from the solution and rapidly cooled in the water at 25and#730;C to prevent phase transformation. Next, quenched samples are subjected to artificial aging at 155and#730;C for a time span of continuous 4 hours. In the end, the cast samples are exposed to cool air until it reaches the room temperature. newline