Effect of Cooling Rates and rapidly quenched on Al-Si alloy

Abstract

Due to its unique properties, the material could be applicable in the automotive industry for the manufacture of exhaust valves, for wear parts, and probably as a material for selected aggressive chemical environments. The solidification behavior of the Al-80.5 % Si-19.5 (A), Al-79% Si21% (B) and Al-77.5 % Si-22.5 % (C) alloys at slowly cooling and Rapidly quenched are reported and discussed. The samples were characterized by X-ray diffraction to calculated lattice constant, optical microscopy and mechanically by (Tensile test, and Hardness) in order to evaluate the response of the heat treatment on the different starting microstructures and mechanical properties.It was found that the lattice parameters for all Si contents decreases with increasing Si content in the solid solution. All mineral compounds formed during hardening were examined by optical microscopy. The highest maximum tensile strength was 120 MPa in the sample Al-22.5Si (Slowly cooled) and 126MPa in the sample Al-22.5Si (rapidly quenched) in the same weight, and highest hardness was 77 HB in the sample Al-22.5Si (Slowly cooled), and 81 HB in the sample Al-22.5Si (rapidly quenched).