Optimization of Centrifugal Casting Parameters to Produce the Functionally Graded Al-15wt%Mg2Si Composites with Higher Tensile Properties

In this paper, based on Taguchi method algorithm with orthogonal arrays, a plan for the experiments is designed and employed to optimize the centrifugal casting effective parameters such as pouring and preheating temperatures, and rotational speed of the mold, each with three different levels to obtain the higher toughness as the quality index (QI) in the centrifugally cast Al-15wt%Mg2Si cylinders. The optimization of the casting parameters was carried out via establishment of a relationship between the morphology/size of the Mg2Si particles and corresponding values of QI for the inner layer of the cylinders. Also in order to response test for QI, the analysis of variance was accomplished on not only casting parameters but also QI values. The results show that by controlling the centrifugal casting parameters, the ratio of sphericity to mean area of the Mg2Si particles (%Sph/m.a) thus QI are improved; so that the optimum values of pouring and preheating temperatures, and rotational speed of the mold, were determined as 800 degrees C, 260 degrees C and 1600 RPM, respectively, in which the cylinders illustrate reasonably ductile features in fracture surface.