The effects of heat treatments in Al-Si-Mg alloys on the microstructure and hardness have been investigated by the optical microscope, scanning electron microscope(SEM), and Rockwell hardness tester. The materials of various compositions are melted in...
The effects of heat treatments in Al-Si-Mg alloys on the microstructure and hardness have been investigated by the optical microscope, scanning electron microscope(SEM), and Rockwell hardness tester. The materials of various compositions are melted in a vacuum induction furnace under argon atmosphere. Five different Al alloys are prepared from commercial purity aluminium, magnesium and Al-25Si alloy. Two types of aging treatments are performed: i) Isothermal aging of the specimens at 150℃, 170℃ and 190℃. ii) Pre-aging of the specimens at 60℃, 80℃ and 100℃, and followed by final-aging at 170℃ and 190℃. After the heat treatments, Rockwell hardness are measured with all the specimens.