分级时效热处理对7A85铝合金结构壁板组织性能的影响  

Effects of Hierarchical Aging Treatment on Microstructure and Properties of 7A85 Aluminum Alloy Panel

作　　者：樊振中 李绍威 许晨玲 何建伟 董哲 陆政 Fan Zhenzhong;Li Shaowei;Xu Chenling;He Jianwei;Dong Zhe;Lu Zheng(Beijing Institute of Aeronautical Materials;Beijing Advanced Engineering Technology and Application Research Center of Aluminum Materials;Dalian Huicheng Aluminum Co.,Ltd.)

机构地区：[1]中国航发北京航空材料研究院 [2]北京市先进铝合金材料及应用工程技术研究中心 [3]大连汇程铝业有限公司

出　　处：《特种铸造及有色合金》2023年第2期152-157,共6页Special Casting & Nonferrous Alloys

基　　金：结构舱段用高强高韧7A85铝合金宽幅薄壁高筋整体成形壁板研制。

摘　　要：以7A85铝合金结构壁板为研究对象,结合力学性能测试与微观组织分析,研究了分级时效热处理温度与时间对7A85铝合金结构壁板组织性能的影响。结果表明,7A85铝合金单级时效热处理析出相主要为Al_(2)Cu相、Mg_(2)Zn_(11)相与G.P.Ⅱ区,与α-Al基体呈半共格关系,在保持较高强度的基础上兼具了良好的塑性。双级时效处理后合金析出相为Mg_(2)Zn_(11)相、Mg_(3.5)Zn_(1.5)相与MgZn_(2)相,强化机制为G.P.Ⅱ区和Mg_(2)Zn_(11)析出相与α-Al基体的半共格晶格畸变强化,屈服强度与硬度有所上升,塑性随之下降。随着时效保温过程的持续进行,析出相转变为Mg_(2)Zn_(11)相、MgZn_(2)相与Al_(2)CuMg相,且MgZn_(2)为主析出相,与α-Al基体的晶格关系转变为完全非共格,强度随之下降,塑性受α-Al基体影响连续上升。The influence of hierarchical aging temperature and time on the microstructure and properties of 7A85 aluminum alloy panel was investigated by the mechanical property test and microstructure analysis. The results indicate that the precipitate phase in 7A85 aluminum alloy after single stage aging are mainly composed of Al_(2)Cu phase, Mg_(2)Zn_(11)phase, and G.P.Ⅱ region, which are semi-coherent with the α-Al matrix, showing excellent plasticity while maintaining high strength. The precipitates of two-stage aging are Mg_(2)Zn_(11), Mg_(3.5)Zn_(1.5),and MgZn_(2), and the strengthening mechanism is characterized by the semi-coherent lattice distortion strengthening between the G.P.Ⅱ region or Mg_(2)Zn_(11)phase and the α-Al matrix, showing a rise of yield strength and hardness as well as descent of the plasticity. The precipitate phase is transformed into Mg_(2)Zn_(11), MgZn_(2),and Al_(2)CuMg phases as the aging process continues, where MgZn_(2)is the major, and the lattice relationship between the MgZn_(2)phase and the α-Al matrix is converted to incoherent completely, leading to a decline of strength, and continuous increase of plasticity under the influence of α-Al matrix.

关 键 词：7A85铝合金 时效热处理 力学性能 微观组织 结构壁板 

分 类 号：TG166.3[金属学及工艺—热处理] TG146.21[金属学及工艺—金属学]