Designing the centrifugal casting process and evaluating the mechanical criteria for the aluminum alloy automobile piston

Pistons require different properties in different areas of their body, such as high thermal fatigue resistance in the top, high wear resistance in the crown area, and low weight in the skirt. On our days, they are not pistons with a composition gradient. The pistons are usually produced with homogeneous composition, in one alloy, existing in some cases incorporations of another material, to improve the mechanical characteristics in a certain area. This current work presents an experimental investigation on manufacturing composite pistons from two aluminum alloys, i.e. each alloy forms a zone in the piston. Therefore, A336 alloy located at the piston skirt, and A242 alloy is located at the piston crown. The affecting parameters are the pouring temperature of the alloys, the rotational speed of the casting mold, and the casting method. Centrifugal casting and permanent casting methods were used. The effects of various parameters on the mechanical properties such as hardness and wear were measured. It was found that the centrifugal casting process can be used as a new and effective method in piston manufacturing compared with the permanent casting process. Good results were obtained at 50 rpm casting mold rotational speed and 745°C alloys pouring temperature.