Strength and ductility optimization of HPDC AlSi8MgCuZn2 alloys by modifying pre-aging treatment  

作　　者：Yuan-hang Jiang Hui-ting Zheng Fei Liu Hai-dong Zhao 

机构地区：[1]National Engineering Research Center of Near-net Shape Forming for Metallic Materials,South China University of Technology,Guangzhou 510641,China

出　　处：《China Foundry》2024年第4期343-351,共9页中国铸造（英文版）

基　　金：financially supported by the Natural Science Foundation of Guangdong Province(Nos.2021A151510042,2021A1515011728);the China Postdoctoral Science Foundation(2022M711190);the National Natural Science Foundation of China(No.51875211);the Key Area Research and Development Program of Guangdong Province(No.2020B010186002)。

摘　　要：Considering the components produced by high pressure die casting(HPDC)process usually with ultra-large sizes and complex morphologies,high temperature solid solution treatment is not a suitable method to further improve their mechanical properties.In this study,two-stage aging treatment with different pre-aging times was designed and employed to further improve the mechanical properties of HPDC Al8SiMgCuZn alloy.The characteristics of precipitates were evaluated by a transmission electron microscope(TEM),and the precipitation strengthening mechanism was discussed.The results reveal that the strengthening is mainly contributed by the precipitation ofβ″phase after two-stage aging,and the number density and size of the precipitates are significantly depended on the pre-aging time.The number density of precipitates is increased with the pre-aging time prolonged from 0 h to 4 h,and then decreases with the further increase of pre-aging time from 4 h to 6 h.The precipitates with the highest density and smallest size are observed after pre-aging for 4 h.After pre-aged at 100℃for 4 h and then artificial aged at 200℃for 30 min,the yield strength of 207 MPa,ultimate tensile strength of 325 MPa and elongation of 7.6%are achieved.

关 键 词：high pressure die cast aluminum alloy microstructural heterogeneity mechanical properties precipitation strengthening two-stage aging 

分 类 号：TG146.21[一般工业技术—材料科学与工程]