Optimization of the heat treatment of rheocast alloyA356- T6

In this work the optimum T6 heat treatment of Sr- modified A356 alloy obtained via cooling slope casting was investigated. This study attempts to find a better mechanical response at the optimum heat treatment process. Moreover, the effect of strontium modifier on T6 heat treatment was discussed in detail. The solution heat treatment and age hardening carried out at the temperature-time of 540 °C for 30min,1h,2h and 4h and artificial aging (160°C,180°C,200 °C) at different time at 0.5h until 12h respectively, enabled the magnesium dissolution, eutectic silicon phase spherodization and magnesium inter-metallic precipitation .The micro hardness results demonstrated that the optimum heat treatment was the solution heat treatment of 2 h at 540°C and artificial aging at 180°C for 3 h which is comparable to other reports. The possible mechanisms involved in achievement of this new short heat treatment are discussed by considering the microstructure and hardness analysis

کلیدواژه ها:

solution ، heat treatment ، rheocast ، artifical aging