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.