Comparison of microstructure and corrosion properties of Al-Zn-Mg-Cu alloys 7150 and 7010
(1.Analysis and Measurement Center, Harbin Institute of Technology, Harbin 150001, China
2.黑龙江省哈尔滨市哈尔滨工业大学分析测试中心)
2.黑龙江省哈尔滨市哈尔滨工业大学分析测试中心)
Abstract: The influence of coarse Cu-bearing particles, matrix and subgrain boundary precipitates on the stress corrosion susceptibility of the Al-Zn-Mg-Cu alloys was investigated. The strength of 7150 alloy is about 15 MPa higher than that of 7010 alloy. The 7010 alloy exhibits higher resistance to stress corrosion cracking as compared with the 7150 alloy. The coarse Cu-bearing particles are detrimental to the resistance to stress corrosion cracking. The increase of size of matrix and subgrain boundary precipitates decreases the susceptibility of stress corrosion. The anodic dissolution and hydrogen embrittlement govern the cracking process. The severity of stress corrosion cracking is shown to be related to the coarse Cu-bearing particles, matrix and subgrain precipitates in Al-Zn-Mg-Cu alloys.
Key words: Al-Zn-Mg-Cu alloy; stress corrosion resistance; heat treatment; Al2CuMg