Microstructure and mechanical properties of 7A56 aluminum alloy after solution treatment  

作　　者：Feng-Bin Guo Bao-Hong Zhu Long-Bing Jin Guo-Jun Wang Hong-Wei Yan Zhi-Hui Li Yong-An Zhang Bai-Qing Xiong 

机构地区：[1]State Key Laboratory of Nonferrous Metals and Processes,General Research Institute for Nonferrous Metals,Beijing 100088,China [2]Northeast Light Alloy Co.,Ltd.,Harbin 150060,China

出　　处：《Rare Metals》2021年第1期168-175,共8页稀有金属（英文版）

基　　金：financially supported by the National Key Research and Development Program of China(No.2016YFB0300803);the National Natural Science Foundation of China(No.51274046);the National Key Basic Research Program(No.2012CB619504)。

摘　　要：The effect of solution treatment on the microstructure and mechanical properties of a novel 7 A56 aluminum alloy plate was investigated by optical microscopy(OM),scanning electron microscopy(SEM),transmission electron microscopy(TEM),X-ray diffraction(XRD),differential scanning calorimetry(DSC),conductivity,hardness and tensile tests.The results indicate that the coarse second phases in the hot-rolled plate mainly consist of AlZnMgCu quaternary phase and Al_(7) Cu_(2) Fe phase,and no Al_(2) CuMg phase is found.The amount of the second phases gradually reduces with the increase in temperature(450-480℃)and time(1-8 h)during the solution treatment,and the soluble particles are completely dissolved into the matrix after solution treatment at 470℃for 4 h,while the residual phases are mainly Fe-rich phase along the grain boundaries.The recrystallization fraction of the alloy gradually increases with the degree of solution treatment deepened.When the temperature exceeds480℃,over-burning takes place.The mechanical properties of samples treated at 470℃for various times were tested.After the solution treated at 470℃for 4 h,the quenching conductivity and peak-aged hardness of the alloy are 30.8%IACS and HV 204,respectively.The ultimate tensile strength and yield strength of the samples aged at 120℃for 24 h are 661 and 588 MPa,respectively.

关 键 词：7A56 aluminum alloy Solution treatment Aging treatment MICROSTRUCTURE PROPERTIES 

分 类 号：TG156.94[金属学及工艺—热处理] TG146.21[金属学及工艺—金属学]