Microstructure and mechanical properties of Al-Si alloy modified with Al-3P
(1. Jiangsu Key Laboratory of Material Surface Science and Technology, Changzhou University, Changzhou 213164, China;
2. Jiangsu Key Laboratory of Oil & Gas Storage and Transportation Technology, Changzhou University, Changzhou 213164, China;
3. Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, China)
2. Jiangsu Key Laboratory of Oil & Gas Storage and Transportation Technology, Changzhou University, Changzhou 213164, China;
3. Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, China)
Abstract: Al-Si alloy was modified with Al-3P master alloy at 740 °C. The effects of Si content (7, 8, 9, 10 and 11 wt.%) and adding amount of alterant Al-3P (0, 0.1, 0.3, 0.6, 1.0 and 1.5 wt.%) on microstructures and tensile properties of the alloy were investigated with optical microscope (OP), Image Pro Plus 6.0, scanning electron microscope (SEM) and universal testing machine. When the content of Al-3P is 0.6 wt.%, the area fraction of primary α(Al) in the Al-Si alloy increases more compared to the unmodified alloy with an increase in Si content, which could be explained by the movement of non-equilibrium eutectic point. When the Si content is constant (Al-10Si), with the increase of Al-3P content, the increased rate in area fraction of primary α(Al) phase in the Al-10Si alloy increases first and then decreases. And when 0.6 wt.% Al-3P is added, the increase in area fraction of primary α(Al) phase is the largest. Compared to the unmodified Al-10Si alloy, the tensile strength and elongation of Al-10Si alloy increase by 2.3% and 47.0%, respectively, after being modified with 0.6 wt.% Al-3P alloy. The fracture mode of the modified Al-10Si alloy is ductile fracture.
Key words: Al-Si alloy; modification; microstructure; mechanical properties; area fraction