The Effect of Thermo-Mechanical Processing on the Microstructure and Mechanical Properties of Modified SIMA Treated Al-7Si Alloy

The effect of holding time and temperature in the Modified Strain Induced Melt Activation process on microstructure and mechanical properties of Al -7 wt% Si alloy was investigated. Al -7 wt% Si alloy was prepared through melting and casting route. The alloy was homogenized at 540 ℃ for 6 h. The plate was deformed 40 and 60% by warm rolling followed by air cooling. The deformed samples were heat treated for different temp. (585, 595 and 605 ℃) and time (10, 30 and 60 min). The microstructure and mechanical properties of Modified SIMA treated samples were evaluated and compared with as-cast samples. It is observed that with increasing isothermal holding temperature and time during Modified SIMA process, the mechanical properties such as yield strength , ultimate tensile strength and hardness are increased but percentage of elongation decreased. The better combination of mechanical properties was obtained when 60% deformed alloy was isothermally hold at temperature 585 ℃ for 30 min.