余聪,陈乐平,周全,袁源平

• 1:南昌航空大学航空制造工程学院

摘要(Abstract)：

对7075铝合金进行T6时效处理和不同电流密度(50～125 A/mm~2)、不同通电时间(480～600 ms)的脉冲电流处理(EPT),采用扫描电镜、透射电镜及万能试验机等研究了合金经不同工艺处理后的显微组织和力学性能。结果表明：与传统的T6时效处理相比，采用合适的电流密度和通电时间的脉冲电流处理，合金的析出相数量、尺寸减小，但能提高位错密度和亚晶数量；且随电流密度和通电时间的增加，第二相回溶数量和亚晶数量不断增加，但位错密度随着电流密度的增加先增大后减小，随着通电时间的增加而不断减小。合金的抗拉强度和伸长率随电流密度和通电时间的增加均为先升高后降低，经固溶+EPT(470℃×3 h+100 A/mm~2×560 ms)后合金的抗拉强度和伸长率达到最高，分别为555 MPa和18%,与T6时效处理相比，抗拉强度下降了2.6%,但伸长率提高了100%。脉冲电流处理的合金的强化机制是固溶强化、位错强化和细晶强化的复合强化机制。

关键词(KeyWords)： 7075铝合金;脉冲电流处理;显微组织;力学性能

Abstract:

Keywords:

基金项目(Foundation): 江西省科技重点研发计划项目(20212BBE53018)

作者(Author): 余聪,陈乐平,周全,袁源平

DOI: 10.13289/j.issn.1009-6264.2023-0130

参考文献(References)：

• [1] 余聪，陈乐平，周全.回归再时效对7075-T8铝合金显微组织及力学性能的影响[J].材料热处理学报，2022,43(8):54-61.YU Cong,CHEN Le-ping,ZHOU Quan.Effect of retrogression and re-aging treatment on microstructure and mechanical properties of 7075-T8 aluminum alloy[J].Transactions of Materials and Heat Treatment,2022,43(8):54-61.
• [2] 程亚军，冷利，宫柏山，等.时效时间对7075铝合金疲劳裂纹扩展速率的影响[J].材料热处理学报，2021,42(5):26-31.CHENG Ya-jun,LENG Li,GONG Bai-shan,et al.Effect of aging time on fatigue crack growth rate of 7075 aluminum alloy[J].Transactions of Materials and Heat Treatment,2021,42(5):26-31.
• [3] 赵晓燕，宋航，王旭.时效工艺对轧制态7075铝合金耐蚀性能的影响[J].材料热处理学报，2018,39(3):21-29.ZHAO Xiao-yan,SONG Hang,WANG Xu.Effect of aging process on corrosion behavior of rolled 7075 aluminum alloy[J].Transactions of Materials and Heat Treatment,2018,39(3):21-29.
• [4] Li H,Jia L,Huang J,et al.Precipitation behavior and properties of extruded 7136 aluminum alloy under different aging treatments[J].Chinese Journal of Aeronautics,2020,34(2):612-619.
• [5] Li Y,Xu G,Peng X,et al.Effect of different aging treatment on high temperature properties of die-forged Al-5.87Zn-2.07Mg-2.42Cu alloy[J].Materials Characterization,2020,164:110239.
• [6] Yang R X,Liu Z Y,Ying P Y,et al.Multistage-aging process effect on formation of GP zones and mechanical properties in Al-Zn-Mg-Cu alloy[J].Transactions Nonferrous Metals Society of China,2016,26(5):1183-1190.
• [7] Liu Y,Jiang D M,Li W J.The effect of multistage ageing on microstructure and mechanical properties of 7050 alloy[J].Journal of Alloys and Compounds,2016,671:408-418.
• [8] Peng G S,Chen K H,Chen S Y,et al.Influence of dual retrogression and re-aging temper on microstructure,strength and exfoliation corrosion behavior of Al-Zn-Mg-Cu alloy[J].Transactions Nonferrous Metals Society of China,2012,22(4):803-809.
• [9] 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.
• [10] Chen K,Zhan L,Yu W.Rapidly modifying microstructure and mechanical properties of AA7150 Al alloy processed with electropulsing treatment[J].Journal of Materials Science and Technology,2021,95:172-179.
• [11] Wang Y,Ke Z,Wu W,et al.Effect of electrical pulse treatment on the retrogression and re-aging behavior of 6061 aluminum alloy[J].Materials Science and Engineering A,2017,703:559-566.
• [12] Xu X F,Yan X D,Qian Y,et al.Ti-6Al-4V alloy strengthening via instantaneous phase transformation induced by electropulsing[J].Journal of Alloys and Compounds,2022,899:163303.
• [13] Pan D,Wang Y T,Guo Q T,et al.Grain refinement of Al-Mg-Si alloy without any mechanical deformation and matrix phase transformation via cyclic electro-pulsing treatment[J].Materials Science and Engineering A,2021,807:140916.
• [14] Wang Y T,Zhao Y G,Xu X F,et al.Simultaneously enhanced strength and ductility of Al-Mg-Si alloys during aging process induced by electro-pulsing treatment[J].Materials,2019,12:1383.
• [15] Kang K,Li D,Wang A,et al.Experimental investigation on aging treatment of 7050 alloy assisted by electric pulse[J].Results in Physics,2020,16:103016.
• [16] Zhang W,Sui M L,Hu K Y,et al.Formation of nanophases in a Cu-Zn alloy under high current density electropulsing[J].Journal of Materials Research,2000,15(10):2065-2068.
• [17] Wang Y C,Wu X D,Yue L,et al.Comparative study of aging precipitation behavior and property of an Al-Zn-Mg-Cu-Zr-Er alloy with different quenching rates[J].Transactions of Nonferrous Metals Society of China,2022,32(4):1070-1082.
• [18] Shan Z H,Yang J,Fan J F,et al.Microstructure evolution and mechanical properties of an AZ61 alloy processed with TS-ECAP and EPT[J].Materials Science and Engineering A,2020,780:139195.
• [19] Xiao S H,Guo J D,Wu S D,et al.Recrystallization in fatigued copper single crystals under electropulsing[J].Scripta Materialia,2002,46:1-6.
• [20] Shan Z H,Bai J,Fan J F,et al.Exceptional mechanical properties of AZ31 alloy wire by combination of cold drawing and EPT[J].Journal Material Science Technology,2020,51:111-118.
• [21] 张美丽，韩茜，李春，等.固溶处理对含稀土 7A04 铝合金组织与性能的影响[J].材料热处理学报，2022,43(6):57-64.ZHANG Mei-li,HAN Xi,LI Chun,et al.Effect of solution treatment on microstructure and properties of 7A04 aluminum alloy containing rare earth[J].Transactions of Materials and Heat Treatment,2022,43(6):57-64.
• [22] Zhang Q,Luan X,Dhawan S,et al.Development of the post-form strength prediction model for a high-strength 6xxx aluminium alloy with pre-existing precipitates and residual dislocations[J].Inter Journal Plasticity,2019,119:230-248.
• [23] Zhou J,Xu S,Shu H,et al.Tensile properties and microstructures of a 2024-T351 aluminum alloy subjected to cryogenic treatment[J].Metals,2016,6(11):279.
• [24] Majchrowicz K,Pakiela Z,Chrominski W,et al.Enhanced strength and electrical conductivity of ultrafine-grained Al-Mg-Si alloy processed by hydrostatic extrusion[J].Materials Characterization,2018,135:104-114.
• [25] Li Y J,Kostka A,Choi P,et al.Mechanisms of subgrain coarsening and its effect on the mechanical properties of carbon-supersaturated nanocrystalline hypereutectoid steel[J].Acta Materialia,2015,84:110-123.

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