Effect of Solution Treatment on Recrystallization, Texture and Mechanical Properties of 7A65-T74 Aluminum Alloy Super-thick Hot Rolled Plate

Abstract

The effects of the solution treatment on the microstructure, recrystallization, texture composition and properties of 7A65-T7451 (120 mm) hot rolled plates at H/2 (1/2 thickness) and H/4 (1/4 thickness) were studied. The results show that the hot rolled microstructure mainly contains a large amount of MgZn₂ phases and minor Al₇Cu₂Fe phase. After solid solution treatments, a large amount of MgZn₂ phases are dissolved back into the aluminum matrix. The main texture types at H/4 are R-Cube, Cube and part of Brass texture, and the main texture types at H/2 are Cube, R, and Copper texture. The qualitative analysis by Schmidt’s law reveals that Copper texture at H/2 will deepen the anisotropy of plate metal properties. For the plate with the same thickness, the two-stage solution state has better mechanical properties due to the lower degree of recrystallization and stronger grain boundary strengthening effects. Under the two-stage solution system of 460 °C/165 min+477 °C/165 min, the composite mechanical properties of the alloy plate at H/4 are the best and the anisotropy is not obvious. The tensile strength, yield strength, and elongation along the rolling direction are 561.9 MPa, 523.4 MPa, and 10.6%, respectively..

Keywords

7A65 thick plate / solid solution treatment / texture / recrystallization / anisotropic

References

[1] Yang S J, Dai S L. A Glimpse at the Development and Application of Aluminum Alloys in Aviation Industry[J]. Materials Review, 2005, 19(2): 76-80.

[2] Sakai Y. Current State and the Future of Aluminum Alloy Applications of Rolling Stock[J]. Journal of Japan Institute of Light Metals, 2006, 55(11): 584-587.

[3] Wang S H, Meng L G, Yang S J, et al. Microstructure of Al-Zn-Mg-Cu-Zr-0.5Er Alloy under As-cast and Homogenization Conditions[J]. Transactions of Nonferrous Metals Society of China, 2011, 21(7): 1449-1454.

[4] Ji H. Application Research on Advanced Aluminum Alloy Forging for Large Airplane[J]. Hot Working Technology, 2014, 43(11): 13-15.

[5] Paul A R, Zhang Y, Steven Knight. Heat Treatment of 7xxx Series Aluminium Alloys—Some Recent Developments[J]. Transactions of Nonferrous Metals Society of China, 2014, 24(07): 2003-2017.

[6] Zhang Z Q, Yu J H, He D Y. Effect of Contact Solid Solution Treatment on Peak Aging of Al-Zn-Mg-Cu Alloys[J]. Journal of Materials Research and Technology, 2020, 9(3): 6940-6943.

[7] Xu X J, Mao Q, Jiang Z, et al. Effect of Multi-stage Solution and Aging Process on Microstructure and Properties of Al-11.2Zn-3.0Mg-1.3Cu-0.2Zr Aluminum Alloy Extrusion[J]. Materials Letters, 2019, 254: 375-378.

[8] Wei L J, Han B S, Ye F, et al. Influencing Mechanisms of Heat Treatments on Microstructure and Comprehensive Properties of Al-Zn-Mg-Cu Alloy Formed by Spray Forming[J]. Journal of Materials Research and Technology, 2020, 9(3): 6850-6858.

[9] Jin W M, Yu J H, Zhang Z Q, et al. Study on Ultra-High Temperature Contact Solution Treatment of Al-Zn-Mg-Cu Alloys[J]. Metals, 2021, 11(5): 842

[10] Hou Y F, Xiao J J, Liu C Y, et al. Effect of Heat Treatment on the Microstructure, Mechanical Properties and Corrosion Resistance of Friction Stir Processed Al-Zn-Mg-Cu-Sc-Zr Alloy[J]. Journal of Materials Engineering and Performance, 2021, 30(5): 3398-3405.

[11] Zhang L L, Wang X J, Wei X L. Evolution of Grain Structure and Texture for 6082-T6 Aluminum Alloy during Friction Stir Welding[J]. Journal of Wuhan University of Technology-Materials Sci. Ed., 2019, 34(2): 397-403.

[12] Zhang X Y, Song R G, Sun B. Effects of Aging Treatment on Intergranular Corrosion and Stress Corrosion Cracking Behavior of AA7003[J]. Journal of Wuhan University of Technology-Materials Sci. Ed., 2018, 33(5): 1198-1204.

[13] Zhao X D, Lu R L, Lin J B, et al. Effects of Deformation Modes on Texture Evolution during Hot Working of Al-Zn-Mg-Cu-Zr Alloy[J]. Journal of Wuhan University of Technology-Materials Sci. Ed., 2016, 31(3): 616-623.

[14] Kang K J, Li D Y, Shi D Q, et al. Evolution of Microstructure and Mechanical Properties in Al-Zn-Mg-Cu Alloy by Electric Pulse Aging Treatment[J]. Transactions of the Indian Institute of Metals, 2021, 74(11): 2835-2842.

[15] Fan C H, Zheng D S, Chen X H, et al. Effect of Large Strain Cross Rolling on Microstructure and Properties of Al-Li Alloy Plates with High Magnesium Content[J]. Transactions of Nonferrous Metals Society of China, 2019, 29(2): 263-269.

[16] Wang X F, Shi T Y, Wang H B, et al. Effects of Strain Rate on Mechanical Properties, Microstructure and Texture of Al—Mg—Si—Cu Alloy under Tensile Loading[J]. Transactions of Nonferrous Metals Society of China, 2020, 30(1): 27-40.

[17] Wang X D, Liu X, Ding H, et al. Microstructure and Mechanical Properties of Al-Mg-Si Alloy U-shaped Profile[J]. Transactions of Nonferrous Metals Society of China, 2020, 30(11): 2915-2926.

[18] Li C, Xiong H Q, Bhatta L, et al. Microstructure Evolution and Mechanical Properties of Al—3.6Cu—1Li Alloy Via Cryorolling and Aging[J]. Transactions of Nonferrous Metals Society of China, 2020, 30(11): 2904-2914.

[19] Wang L, Yang X F. Microstructural Evolution of Cold-Rolled AA7075 Plate During Solution Treatment[J]. Materials, 2020, 13(12): 2734

[20] Feng S, Sun L M, Chen Z G, et al. Microstructure and Mechanical Properties of 7056 Aluminum Alloy Thick Plates[J]. Rare Metal Materials and Engineering, 2018, 47(10): 3088-3095. (in Chinese)

[21] Li Y, Xu G F, Liu S C, et al. Study on Anisotropy of Al-Zn-Mg-Sc-Zr Alloy Plate[J]. Materials Characterization, 2021, 172: 110904.

[22] Fan X Y, Li Y, Xu C, et al. Improved Mechanical Anisotropy and Texture Optimization of a 3xx Aluminum Alloy by Differential Temperature Rolling[J]. Materials Science and Engineering: A, 2021, 799: 140278.

[23] Cusset R, Azzouz F, Besson J, et al. Modeling Plasticity of an Aluminum 2024T351 Thick Rolled Plate for Cold Forming Applications[J]. International Journal of Solids and Structures, 2020, 202: 463-474.

[24] Zang Q H, Feng D, Lee Y S, et al. Microstructure and Mechanical Properties of Al-7.9Zn-2.7Mg-2.0Cu (wt%) Alloy Strip Fabricated by Twin Roll Casting and Hot Rolling[J]. Journal of Alloys and Compounds, 2020, 847: 156481.

[25] Ma Y L, Li J F, Zhang R Z, et al. Strength and Structure Variation of 2195 Al-Li Alloy Caused by Different Deformation Processes of Hot Extrusion and Cold-Rolling[J]. Transactions of Nonferrous Metals Society of China, 2020, 30(4): 835-849.

[26] Deng Y L, Wan L, Zhang Y, et al. Evolution of Microstructures and Textures of 7050 Al Alloy Hot-Rolled Plate During Staged Solution Heat-Treatments[J]. Journal of Alloys and Compounds, 2010, 498: 88-94.

[27] Soyama J, Rios C T. Effect of Subcritical Annealing on the Microstructure and Mechanical Properties of a Precipitation-Hardened Al-Zn-Mg-Cu Alloy[J]. Journal of Materials Engineering and Performance, 2021, 30(2): 1012-1021.

[28] Lin A N, Jiang S S, Peng B S, et al. Mechanical Properties and Electrical Conductivity of Aluminum Alloys[J]. Light Metals, 2005(06): 34–36

[29] She X W, Jiang X Q, Wang P Q, et al. Relationship between Microstructure and Mechanical Properties of 5083 Aluminum Alloy Thick Plate[J]. Transactions of Nonferrous Metals Society of China, 2020, 30(7): 1780-1789.

[30] Chen L, Yuan S W, Kong D M, et al. Influence of Aging Treatment on the Microstructure, Mechanical Properties and Anisotropy of Hot Extruded Al-Mg-Si Plate[J]. Materials & Design, 2019, 182: 107999.

[31] Zhang K, He Q S, Rao J H, et al. Correlation of Textures and Hemming Performance of an AA6XXX Aluminium Alloy[J]. Journal of Alloys and Compounds, 2021, 853: 157081.

[32] Margulies L, Winther G, Poulsen H F. In Situ Measurement of Grain Rotation during Deformation of Polycrystals[J]. Science, 2001, 291: 2392-2394.

[33] Li S S, Zhao Q, Liu Z Y, et al. A Review of Texture Evolution Mechanisms During Deformation by Rolling in Aluminum Alloys[J]. Journal of Materials Engineering and Performance, 2018, 27(7): 3350-3373.

[34] Hutchinson W B. Development and Control of Annealing Textures in Low-Carbon Steels Inter[J]. Metals Rewiews, 1984, 29: 25-42.

[35] Shackelford J F. Introduction to Materials Science for Engineers[M], 1992 3rd ed. New York: Mcmillan Pub. Co..

[36] Yang G, Chen L W, Wang J H, et al. Influences of Texture of FCC Metals on Their Mechanical Properties[J]. Journal of Kunming University of Science and Technology(Natural Sciences), 2012, 37(05): 24-27.

[37] Marthinsen K, Nes E. A General Model for Metal Plasticity[J]. Materials Science and Engineering A, 1997(234/235/236): 1095–1098