Achieving high strength and ductility in double-sided friction stir processing 7050-T7451 aluminum alloy

作者：Yang, Wenjing; Ding, Hua^*; Mu, Yongliang; Li, Jizhong; Zhang, Wenjing

来源：Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 2017, 707: 193-198.

DOI：10.1016/j.msea.2017.09.028

• Friction stir processing
• Aluminum alloy
• Solution treatment
• Microstructure
• Microhardness

In this paper, a novel approach named double-sided friction stir processing (DFSP) was proposed to prepare 7050-T7451 aluminum alloy plates, and effects of solution treatment (ST) on microstructures and mechanical properties of DFSP were investigated. The solution treatment at 470 degrees C for 4.5 h was employed. 7050-T7451 and 7050-ST aluminum alloy plates were used for DFSP, and their experimental results were compared. A significant grain refinement to an average 1.5-2.2 mu m was attained by DFSP for both 7050-T7451 and 7050-ST plates. The microstructure exhibits a bimodal character which consists of fine grains with the size of 1-6 mu m and ultrafine grains with the size of 1 gm. The precipitated particles in the SZ of T7451-DFSPed and ST-DFSPed plates are MgZn2 and MgAlCu/Al7Cu2Fe. Compared with the T7451-DFSPed plate, the ST-DFSP one shows a higher dissolution degree of Mg and Zn elements, and most dispersoid are retained as eta' phase, additionally, the homogenization of the microhardness distribution of the ST-DFSP plate is improved and a higher tensile strength is obtained while good ductility is maintained.

• 出版日期2017-11-7
• 单位东北大学; 中国航空工业集团公司北京航空制造工程研究所