Structure and properties of an ultra-high strength 7xxx aluminum alloy contained Sc and Zr

Xiaoyuan Dai~(1,2)) Changqing Xia~(1)) Xiaomin Peng~(1)) Ke Ma~(1)) 1)School of Materials Science and Engineering,Central South University,Changsha 410083,China 2)School of Materials Science and Engineering,Changsha University of Science and Technology,Changsha 410076,China

摘 要：<正>An ultra-high strength aluminum alloy was produced by casting and then extruded to rods.The effect of heat treatment on the microstructure and mechanical properties of the alloy was investigated.After single ageing（120℃,24 h）,the tensile strength was 812.4 MPa and the elongation was 6.2%.After retrogression reaging（RRA）,the tensile strength was 751.2 MPa and the elongation was 6.4%.The strengthening mechanism is considered as fine grain strengthening,substructure strengthening and dispersion strengthening by Al₃（Sc,Zr）.

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