Effect of Cooling Conditions on Microstructures and Properties of Al-Si-Mg Alloys for Heat Dissipation
Author of the article:FAN Weizhong;YAN Jun;HUANG Pengyu;WANG Yajing;CAI Yunlong;ZHU Huiying;WENG Wenping;Hiromi Nagaumi
Author's Workplace：Huajin New Material Research Institute(GUANZHOU)Co.,Ltd.,Guangzhou 510000,China;School of Iron and Steel,Soochow University,Suzhou 215000,China
Key Words：Al-Si-Mg alloys cooling rate microstructures thermal conductivity
Abstract：Al-9 Si-0.3 Mg alloy were prepared by different casting cooling methods(such as water-cooled copper mold,forced-cooling,air-cooling),and the effect of different cooling conditions on the microstructure and heat transfer performance of Al-9 Si-0.3 Mg alloy was studied.The results show that the cooling mode has a significant effect on the strength and thermal conductivity of Al-9 Si-0.3 Mg alloy.With the increase of cooling strength,the primaryα-Al gradually becomes uniform,and eutectic Si gradually becomes fine and round.The yield strength and elongation of Al-9 Si-0.3 Mg alloy increase significantly,while the thermal conductivity decreases slightly.When the cooling strength is low,the amount of solid solution of reinforcing elements in Al matrix decreases,and more of them exist in the form of precipitation of the second phase,which is beneficial to improve the thermal conductivity of materials.The yield strength,elongation and thermal conductivity are 126.0 MPa,4.2%and 141.9 W/m·K,respectively,when the forced-cooling mode with medium cooling strength is adopted.
