Design and manufacturing of Al-Mg2Si cylindrical functionally graded composites using in-situ centrifugal casting

In recent decades, the use of metal matrix composites and functionally graded materials for achieving a combination of mechanical and physical properties has increased. In this research, an in-situ centrifugal casting method was used to make the samples. The primary composite used in this method was Al-15wt.% Mg2Si. In situ prepared functionally graded samples were successfully manufactured at 1000, 1300, and 1700 rpm rotational speeds. Optical microscopy was used to examine the microstructure of the samples, and a Vickers hardness tester was used to examine the mechanical properties. The cross-section of the fabricated samples was divided into two parts, the reinforced and the matrix parts. Porosity increased as a destructive parameter in the reinforced area. The hardness increased as the volume fraction of particles in the reinforced area was increased. Also, hardness increased in the chilled zone due to the fine-grains and trapped particles in that area. Solutionizing heat treatment was performed for the fabricated samples. By observing the microstructure, there was no change in the placement trend of the primary particles, but the morphology of the primary and eutectic Mg2Si particles were changed. Hardness increased after heat treatment while its gradient did not change.