Effect of The Pressure of the Squeeze Process on the Hardness and Micro Structure of Recycled Aluminum Materials

Abstract

A squeeze casting process produces the final accurate products with good quality. It casted microstructure results look more dense and homogeneous and have good mechanical properties when compared with those of foundry castings. The recycled materials used were 25 kg piston aluminum alloys, 25 kg and 25 kg wheel in the form of a mixture (brake, engine cover, and household furnishings) that were melted in the processing unit. The process of compacting system is undertaken with a direct squeeze casting technique. The molten metal was poured into a mold at a temperature of 750 ° C, and then pressed for 60 to 70 seconds. The pressure process of 30 MPa is applied for duration of 75 seconds. The pressure process was repeated at 50,70,90,110 MPa, 130 and 150 MPa and the casted material was removed from the body casting in the mold. The composition of the test results of recycled aluminum is 84.75% Al and 8.985% Si, with surface hardness 130 MPa at a pressure of 89.74 HBN. The squeeze casting process increases surface hardness by 22%. The hardness of squeeze surface was influenced by the pouring temperature, the time pressure and the force suppression. The microstructure of the materials tends to move up and retracts with increasing of applied pressure.