Investigation on the Tensile Strength and Microhardness of AA6061/TiC Composites by Stir Casting

AA6061 is widely used in aircraft, marine and automobile industries for its high strength to weight ratio, good ductility and corrosion resistance. The stir casting process parameters play a vital role in deciding the particle dispersion and the mechanical strength of the composites. In this paper, an attempt has been made to develop the empirical relationship to predict tensile strength and microhardness of the AA6061 reinforced with TiC by incorporating the process parameters such as stirrer blade angle (alpha), stirring speed (N) and stirring time (T) whose values were optimized. Three factors, five level central composite design has been used to minimize the number of experimental conditions. Response surface method has been used for developing the mathematical model, which can be used to predict the tensile strength and the microhardness of the cast composites at 95 % confidence level. The result indicates that the stirrer blade angle alpha has the greatest influence on the tensile strength and microhardness followed by N and T.