Heat treatment of A356.2 aluminum alloy: Effect of quench rate and natural ageing

A356.2 aluminum alloy is a popular commercial alloy used for structural shaped castings in automotive applications. The heat treatment of this alloy is critical to obtain the desired mechanical and performance properties. The three stages of heat treatment include, solutionizing, quenching and artificial ageing. In this study, the effect of quenching in water at 80 °C and forced air at 37.4 ms^-1 velocity is quantified. Further, the effect of natural ageing treatment prior to the artificial ageing is also quantified. It is observed that the mechanical properties of the castings are significantly affected by both the rate of quenching and the natural ageing treatment. Mechanical properties and hardness values are presented for standard uniaxial tensile test specimen cast by gravity permanent mold process and subjected to various heat treatment conditions.