Modification Effects of Sb on Al7SiMg Alloy Measured with Cooling Curve Analysis

Abstract:

The modification mechanism of Sb on eutectic Si phase of Al-Si alloys was not understood very well. In this paper the modification effects of Sb on Al7SiMg alloy were investigated by computer aided cooling curve thermal analysis coupled with microstructure observation. The results show that the addition of Sb with 0.1%~0.25% amount has refining effect on eutectic Si phase, and this modification effect can be recorded by the cooling curve. The addition of Sb decreases the growth temperature of the eutectic solidification (T_EG) by 5.0 °C to 7.8 °C, and this indicates that there is an undercooling effect with Sb modification. Moreover, faster cooling rate can obtain more superior morphology of eutectic Si, which can be changed from short rod to nearly granular particles. The morphology of eutectic Si is nearly unchanged with holding time extending from 0.5h to 2.5h, which means Sb has long modification effect for Al-Si alloys.

• Periodical: Materials Science Forum (Volume 879)
• Pages: 2113-2118
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.879.2113
• Online since: November 2016
• Authors: Shu Sen Wu, Meng Jie Lü*, Jian Xun Chen, You Wu Mao, Shu Lin Lü
• Keywords: Aluminum Alloy, Antimony, Cooling Rate, Modification, Thermal Analysis

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