Effect of deformation induced precipitation on microstructure and properties of 7A20 aluminum alloy

doi:10.13251/j.issn.0254-6051.2020.07.016

Abstract

Abstract: Effect of pre-deformation temperature and pre-precipitation time on precipitation behavior of the second phase,microstructure and mechanical properties of 7A20 aluminum alloy was investigated by means of OM, SEM, TEM, XRD and tensile tester. The results indicate that the average size of MgZn₂ phase in the tested alloy is about 0.1 μm, and the fraction of precipitation phase is the most and distributed uniformly when deformed at 400 ℃. The peak value of yield strength and tension strength of the alloy are 170 MPa and 310 MPa, respectively, after pre-precipitation at 400 ℃ for 2 h, while the elongation reaches 20%. The fracture morphologies all exhibit ductile fracture characteristics. XRD peak of MgZn₂ phase precipitates exists in the range of 40°-45° after hot rolling and pre-precipitation. The size of MgZn₂ phase is about 0.1-0.2 μm, 0.3-0.8 μm and 0.6-1.0 μm after pre-precipitation for 1 h, 2 h and 4 h, respectively. The density of MgZn₂ phase decreases with the increase of pre-precipitation time.

Key words: 7A20 aluminum alloy, strain-induced precipitation, microstructure, mechanical properties

CLC Number:

TG142.1

Jiang Shaojing. Effect of deformation induced precipitation on microstructure and properties of 7A20 aluminum alloy[J]. Heat Treatment of Metals, 2020, 45(7): 78-82.

References

[1]Miller W S, Zhuang L, Bottema J, et al. Recent development in aluminum alloys for the automotive industry[J]. Materials Science and Engineering A, 2000, 280(1): 37-49.
[2]Hirsch J. Recent development in aluminum for automotive applications[J]. Transactions of Nonferrous Metals Society of China, 2014, 24(7): 1995-2002.
[3]Zhou J, Wan X M, Li Y. Advanced aluminium products and manufacturing technologies applied on vehicles presented at the EuroCarBody conference[J]. Materials Today: Proceedings, 2015, 2(10): 5015-5022.
[4]Shin J, Kim T, Kim D E, et al. Castability and mechanical properties of new 7××× aluminum alloys for automotive chassis/body applications[J]. Journal of Alloys and Compounds, 2017, 698: 577-590.
[5]Fridlyander I N, Sister V G, Grushko O E, et al. Aluminum alloys: Promising materials in the automotive industry[J]. Metal Science and Heat Treatment, 2002, 44(9/10): 365-370.
[6]Tucker Reginald. Trends in automotive lightweighting[J]. Metal Finishing, 2013, 111(2): 23-25.
[7]倪军, 罗益民, 甘甜, 等. 铝合金2219-O热拉伸流变行为研究[J]. 塑性工程学报, 2018, 25(4): 106-112.
Ni Jun, Luo Yimin, Gan Tian, et al. Thermal tensile rheological behavior of aluminum alloy 2219-O[J]. Journal of Plasticity Engineering, 2018, 25(4): 106-112.
[8]Wu B, Li M Q, Ma D W. The flow behavior and constitutive equations in isothermal compression of 7050 aluminum alloy[J]. Materials Science and Engineering A, 2012, 542: 79-87.
[9]Merati A, Eastaugh G. Determination of fatigue related discontinuity state of 7000 series of aerospace aluminum alloys[J]. Engineering Failure Analysis, 2017, 14(4): 673-685.
[10]She H, Shu D, Chu W, et al. Effects of Fe and Si impurities on the microstructure and properties of 7××× high strength aircraft aluminum alloys[J]. Journal of Materials Engineering, 2013, 6: 92-98.
[11]Li D F, Zhang D Z, Liu S D, et al. Dynamic recrystallization behavior of 7085 aluminum alloy during hot deformation[J]. Transactions of Nonferrous Metals Society of China, 2016, 26(6): 1491-1497.
[12]Zhang H, Li L X, Yuan D. Hot deformation behavior of the new Al-Mg-Si-Cu aluminum alloy during compression at elevated temperatures[J]. Materials Characterization, 2007, 58(2): 168-173.

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