Study of the Effect of Process Parameters on Mechanical Properties and Microstructure of Al-Cu and SiCp Reinforced Metal Matrix Composite

The high cost of fabrication hindered the actual application of metal matrix composite (MMC) despite of their high stiffness, strength, corrosion resistance, wear resistance, non-reactivity with chemicals and so many other tailored quality which are never obtained in alloy of metals. In this study, a modest attempt has been made to find out the process parameters at which best mechanical properties of Al6061, 4%Cu and reinforced 5% SiCp ceramic MMC can be obtained. Addition of 4% Cu in Al6061 is more or less comparable to the composition of duralumin, which is widely used in aerospace applications. SiCp is hard and having linear thermal expansion at high temperature. With reinforcement of SiCp in Al-Cu alloy, it can be postulated that hardness of MMC retains at high temperature applications. An analysis of Variance (ANOVA) was used for analysis of data with the help of SPSS (Version-17.0) software. Independent parameters are three levels of pouring rates (1.5cm/s, 2.5 cm/s and 3.5 cm/s), material type (Al6061+4%Cu alloy and Al+4%Cu, reinforced 5%SiCp MMC processed using stir casting technique) and dependent parameters are hardness and impact strength, which is found that at different pouring rates material hardness and impact strength are highly significant. At pouring rate of 2.5 cm/s and 700±5 ̊C pouring temperature, optimum values of hardness and impact strength are observed as compared to other values of pouring rates (1.5 cm/s and 3.5 cm/s). With reinforcement of 5% SiC trend of mechanical properties is same, but hardness and impact strength of MMCs are increased by 25% and 20% respectively. Also it is observed from scanning electron microscopy (SEM) that at pouring rate 2.5 cm/s a better homogeneity can be obtained.