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
• 来源期刊: 稀有金属（英文版）
• 年，卷（期）: 2021,（1）
• 所属期刊栏目: ORIGINAL ARTICLES
• 页码范围: 168-175
• 页数: 8页
• 语种: 英文

摘要

The effect of solution treatment on the microstructure and mechanical properties of a novel 7A56 aluminum alloy plate was investigated by optical micro-scopy(OM),scanning electron microscopy(SEM),trans-mission electron microscopy(TEM),X-ray diffraction(XRD),differential scanning calorimetry(DSC),conduc-tivity,hardness and tensile tests.The results indicate that the coarse second phases in the hot-rolled plate mainly consist of AlZnMgCu quaternary phase and Al7Cu2Fe phase,and no Al2CuMg 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 exceeds 480℃,over-burning takes place.The mechanical prop-erties 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 ulti-mate tensile strength and yield strength of the samples aged at 120℃for 24 h are 661 and 588 MPa,respectively.