INVESTIGATION ON THE INFLUENCE OF HEAT TREATMENT OF MECHANICAL BEHAVIOR ENHANCEMENT OF A356 ALLOY

In this present work, A356 aluminum alloy is heat treated with the addition of copper, rare earth and strontium were investigated. T6 treatment is preferred in this work (solution at 535°C for 4h + aging at 150°C for 15h) when compared to other heat treatment processes (i.e short heat treatment processes). The effects of heat treatment on microstructure and tensile properties of the Al-7%Si-0.3%Mg alloys were investigated by optical microscopy and tension test. It is found that a 2h solution at 550°C is sufficient to make homogenization and saturation of magnesium and silicon in (Al) phase, spheroid of eutectic Si phase. Followed by solution, a 2h artificial aging at 170°C is almost enough to produce hardening precipitates. Those samples treated with T6 achieve the maximum tensile strength and fracture elongation. With short time treatment (ST), samples can reach 90% of the maximum yield strength, 95% of the maximum strength and 80% of the maximum elongation.