李茂华,陈志龙,徐伊雯,卢立伟,杨延清,孙佳林

• 1:湖南科技大学材料科学与工程学院
• 2:西北工业大学材料学院

摘要(Abstract)：

采用透射电镜和万能材料试验机研究了双级时效处理中终时效对7475铝合金微观组织和力学性能的影响。结果表明：当一级时效工艺为120℃×5 h及终时效工艺为160℃×14 h时，合金基体析出相数量多，且细小弥散，晶界无沉淀析出带较窄，晶界析出相且呈断续分布；此时合金的抗拉强度、屈服强度和伸长率最佳，分别为509 MPa、463 MPa和12.4%,与未处理的合金相比，抗拉强度、屈服强度和伸长率分别提高了4.5%、9.2%和11.7%;终时效温度为160℃时，随着终时效时间的延长，合金的强度先增后减，但变化幅度不大；终时效温度大于等于165℃时，随着终时效时间的延长，合金的强度显著降低，这是由于晶界无沉淀析出带宽度显著变宽，基体析出相尺寸明显粗化所致。

关键词(KeyWords)： 7475铝合金;双级时效;终时效;力学性能;微观组织

Abstract:

Keywords:

基金项目(Foundation): 国家自然科学基金(52174362,51975207);; 湖南省自然科学基金(2023JJ50231)

作者(Author): 李茂华,陈志龙,徐伊雯,卢立伟,杨延清,孙佳林

DOI: 10.13289/j.issn.1009-6264.2023-0047

参考文献(References)：

• [1] 刘兵，彭超群，王日初，等.大飞机用铝合金的研究现状及展望[J].中国有色金属学报，2010,20(9):1705-1715.LIU Bing,PENG Chao-qun,WANG Ri-chu,et al.Recent development and prospects for giant plane aluminum alloys[J].The Chinese Journal of Nonferrous Metals,2010,20(9):1705-1715.
• [2] Dong P X,Chen S Y,Chen K H.Effects of Cu content on microstructure and properties of super-high-strength Al-9.3Zn-2.4Mg-xCu-Zr alloy[J].Journal of Alloys and Compounds,2019,788:329-337.
• [3] Wang Y C,Wu X D,Cao L F,et al.Effect of Ag on aging precipitation behavior and mechanical properties of aluminum alloy 7075[J].Materials Science and Engineering A,2021,804:140515.
• [4] Lezaack M B,Hannard F,Zhao L,et al.Towards ductilization of high strength 7XXX aluminium alloys via microstructural modifications obtained by friction stir processing and heat treatments[J].Materialia,2021,20:101248.
• [5] Rometsch P A,Zhang Y,Knight S.Heat treatment of 7xxx series aluminium alloys—some recent developments[J].Transactions of Nonferrous Metals Society of China,2014,24(7):2003-2017.
• [6] Chen J F,Zhang X F,Zou L C,et al.Effect of precipitate state on the stress corrosion behavior of 7050 aluminum alloy[J].Materials Characterization,2016,114:1-8.
• [7] Lin L H,Liu Z Y,Ying P Y,et al.Improved stress corrosion cracking resistance and strength of a two-step aged Al-Zn-Mg-Cu Alloy using taguchi method[J].Journal of Materials Engineering & Performance,2015,24(12):4870-4877.
• [8] Wang Y C,Liu M W,Xiao W L,et al.Effects of multi-stage aging treatments on the precipitation behavior and properties of 7136 aluminum alloy[J].Journal of Alloys and Compounds,2020,814:152256.
• [9] Wang T,Yang L,Tang Z F,et al.Effect of aging treatment on microstructure,mechanical and corrosion properties of 7055 aluminum alloy prepared using powder by-product[J].Materials Science and Engineering A,2021,822:141606.
• [10] Li H Y,Jia L N,Huang J N,et al.Precipitation behavior and properties of extruded 7136 aluminum alloy under different aging treatments[J].Chinese Journal of Aeronautics,2021,34(2):612-619.
• [11] Emani S V,Benedyk J,Nash P,et al.Double aging and thermomechanical heat treatment of AA7075 aluminum alloy extrusions[J].Journal of Materials Science,2009,44(26):6384-6391.
• [12] 龙涛，邓运来，范世通，等.基于正交试验的7085铝合金双级时效制度[J].中南大学学报(自然科学版),2018,49(4):809-816.LONG Tao,DENG Yun-lai,FAN Shi-tong,et al.Two-step aging treatment of 7085 alloy with orthogonal experiment[J].Journal of Central South University (Science and Technology),2018,49(4):809-816.
• [13] 韩宝帅，曾元松，荣刚，等.双级峰时效对超高强Al-Zn-Mg-Cu合金微观组织与力学性能影响[J].中国有色金属学报，2021,32(3):679-691.HAN Bao-shuai,ZENG Yuan-song,RONG Gang,et al.Effect of two-stage peak ageing on microstructure and mechanical properties of the ultra-high strength Al-Zn-Mg-Cu alloy[J].The Chinese Journal of Nonferrous Metals,2021,32(3):679-691.
• [14] 张静，杨亮，左汝林.固溶时效工艺对7055铝合金组织和力学性能的影响[J].稀有金属材料与工程，2015,44(4):956-960.ZHANG Jing,YANG Liang,ZUO Ru-lin.Effects of solution and aging treatments on the microstructures and mechanical properties of 7055 Al alloys[J].Rare Metal Materials and Engineering,2015,44(4):956-960.
• [15] 陈送义，陈康华，董朋轩，等.双级时效对7085铝合金组织和性能的影响[J].中国有色金属学报，2015,25(10):2688-2694.CHEN Song-yi,CHEN Kang-hua,DONG Peng-xuan,et al.Effect of two-step aging on microstructure and properties of 7085 aluminum alloy[J].The Chinese Journal of Nonferrous Metals,2015,25(10):2688-2694.
• [16] 陈志龙，李茂华，杨延清，等.预时效对7475铝合金微观组织和力学性能的影响[J].塑性工程学报，2022,29(11):240-247.CHEN Zhi-long,LI Mao-hua,YANG Yan-qing,et al.Effect of pre-aging on microstructure and mechanical properties of 7475 aluminum alloy[J].Journal of Plasticity Engineering,2022,29(11):240-247.
• [17] 段水亮，刘志义，段安静，等.双级时效对7475铝合金组织与性能的影响[J].金属热处理，2008,33(8):112-115.DUAN Shui-liang,LIU Yong-yi,DUAN An-jing,et al.Effect of two-step aging on microstructure and properties of 7475 aluminum alloy[J].Heat Treatment of Metals,2008,33(8):112-115.
• [18] 程勇胜，郑子樵，李秋菊.时效制度对7475铝合金组织与性能的影响[J].轻合金加工技术，2001,29(6):40-44.CHENG Yong-sheng,ZHEN Zi-qiao,LI Qiu-ju.Effects of aging on microstructure and properties of 7475 aluminum alloy[J].Light Alloy Fabrication Technology,2001,29(6):40-44.
• [19] 李茂华，杨延清，汝继刚，等.热暴露对7475-T761铝合金微观组织和力学性能的影响[J].中国有色金属学报，2022,32(2):353-364.LI Mao-hua,YANG Yan-qing,RU Ji-gang,et al.Effect of thermal exposure on microstructure and mechanical properties of 7475-T761 Al alloy[J].The Chinese Journal of Nonferrous Metals,2022,32(2):353-364.
• [20] Wang S S,Jiang J T,Fan G H,et al.Accelerated precipitation and growth of phases in an Al-Zn-Mg-Cu alloy processed by surface abrasion[J].Acta Materialia,2017,131:233-245.
• [21] Ren J P,Song R G.Strengthening mechanism of two-stage double-peak aging in 7050 aluminum alloy[J].Rare Metal Materials and Engineering,2020,49(4):1159-1165.
• [22] 刘刚，丁向东，孙军，等.具有盘状析出相铝合金的时效强化模型[J].中国有色金属学报，2001,11(3):337-347.LIU Gang,DING Xiang-dong,SUN Jun,et al.A model for age strengthening of plate-like-precipitate-containing Al alloys[J].The Chinese Journal of Nonferrous Metals,2001,11(3):337-347.
• [23] 陈军洲，吕良星，甄良，等.AA 7055铝合金时效析出强化模型[J].金属学报，2021,57(3):353-362.CHEN Jun-zhou,Lü Liang-xing,ZHEN Liang,et al.Precipitation strengthening model of AA 7055 aluminium alloy[J].Acta Metallurgica Sinica,2021,57(3):353-362.
• [24] Shercliff H R,Ashby M F.A Process model for age hardening of aluminum alloys—Ⅰ.the model[J].Acta Metallurgica et Materialia,1990,38(10):1789-1802.
• [25] Du Z W,Sun Z M,Shao B L,et al.Quantitative evaluation of precipitates in an Al-Zn-Mg-Cu alloy after isothermal aging[J].Materials Characterization,2006,56(2):121-128.
• [26] Kamp N,Sinclair I,Starink M J.Toughness-strength relations in the overaged 7449 Al-based alloy[J].Metallurgical and Materials Transactions A,2002,33(4):1125-1136.
• [27] Gokhale A M,Deshpande N U,Denzer D K,et al.Relationship between fracture toughness,fracture path,and microstructure of 7050 aluminum alloy:Part II.multiple micromechanisms-based fracturetoughness model[J].Metallurgical and Materials Transactions A,1998,29(4):1203-1210.

文章评论(Comment)：