Effect of rolling on microstructure of 7050 aluminum alloy FSW joint

Abstract

Abstract: The 5 mm-thick joint of 7050 aluminum alloy friction stir welding was rolled by self-made rolling tool on the surface, and the surface roughness, deformation degree and microstructure evolution of the joints before and after rolling were analyzed. The results showed that the surface roughness of the joint is improved after rolling, and R_a decreases from 7.45 μm as-welded to 6.82 μm. The depth direction of the joint is divided into three layers from the surface down, which are the deformation layer, transition layer and microplastic deformation layer. The deformation layer is the microregion with the most significant strain, the strain of which shows the gradient distribution. The surface deformation is the largest and decreases with increasing depth from the joint surface. The deformed layer undergoes maximum deformation as a result of which the original isoaxial grain in the nugget zone is deformed and refined, forming nanostructures of varying thickness within a certain depth from the joint surface.

Key words: friction stir welding, rolling, surface nanocrystallization, deformation parameters, microstructure

CLC Number:

TG453

JIN Yu-hua, ZHOU Zi-zheng, XING Yi-chu, WU Bo. Effect of rolling on microstructure of 7050 aluminum alloy FSW joint[J]. Journal of Lanzhou University of Technology, 2023, 49(4): 30-34.

References

[1] 张华,郭启龙,赵常宇,等.双级时效对7050-T7451铝合金搅拌摩擦焊组织及应力腐蚀敏感性的影响 [J].焊接学报,2020,41(6):1-5,97.
[2] 贺地求,薛飞,孙友庆.C18150合金搅拌摩擦焊焊缝微观组织与力学性能分析 [J].焊接学报,2019,40(11):93-99.
[3] 王磊,易幼平,黄始全,等.固溶前深冷变形处理对7050铝合金组织和性能的影响 [J].材料导报,2019,33(20):3467-3471.
[4] MA C Q,HOU L G,ZHANG J S,et al.Effect of deformation routes on the microstructures and mechanical properties of the asymmetrical rolled 7050 aluminum alloy plates [J].Materials Science and Engineering A,2018,773:304-315.
[5] 王磊,付强,安金岚,等.2A12-T4铝合金搅拌摩擦焊多区域疲劳裂纹扩展行为 [J].焊接学报,2021,42(2):24-29.
[6] LEE H H,YOON J I,PARK H K,et al.Unique microstructure and simultaneous enhancements of strength and ductility in gradient-microstructured Cu sheet produced by single-roll angular-rolling[J].Acta Materialia,2019,166:638-649.
[7] 王强,高国强,罗学昆.激光喷丸与机械喷丸复合强化对2124-T851铝合金疲劳寿命的影响 [J].表面技术,2021,50(4):96-102.
[8] CHAN H L,RUAN H H,CHEN A Y,et al.Optimization of the strain rate to achieve exceptional mechanical properties of 304 stainless steel using high speed ultrasonic surface mechanical attrition treatment [J].Acta Materialia,2010,58(15):5086-5096.
[9] LEI Y B,WANG Z B,XU J L,et al.Simultaneous enhancement of stress-and strain-controlled fatigue properties in 316L stainless steel with gradient nanostructure [J].Acta Materialia,2019,168(15):133-142.
[10] HEILMANN P,RIGNEY D A.An energy-based model of friction and its application to coated systems [J].Wear,1981,72(2):195-217.
[11] MARTINEZ-ESNAOLA J M,MONTAGNAT M,DUVAL P,et al.Geometrically necessary dislocations in a c-axis oriented cylindrical bar of basal-slipping hexagonal crystals deformed in torsion [J].Scripta Materialia,2004,50(2):273-278.
[12] LU K.Stabilizing nanostructures in metals using grain and twin boundary architectures [J].Nature Reviews Materials,2016,1(5):1-13.

[1]	ZHANG Jie, ZHANG Yu, WANG Ping-bo, WANG Kai-long LAN Ye-feng, LI Qing-lin. The influences of trace Fe,Ni and Ti complex addition on the microstructure and mechanical properties of Al-20Si alloy [J]. Journal of Lanzhou University of Technology, 2023, 49(4): 11-16.
[2]	YIN Xiang, MA Cheng-yan, ZHOU Kai, WANG Xin-min, WANG Yi, WEI Heng-li. Effect of WC content on microstructure and fribological properties of directional Ni60 coating [J]. Journal of Lanzhou University of Technology, 2023, 49(4): 17-23.
[3]	ZHAO Yan-chun, SHI Zi-qiang, ZHANG Lin-hao, ZHANG Min-ya, KOU Sheng-zhong. Effect of homogenization treatment on the microstructure and mechanical properties of Fe-based medium entropy alloys [J]. Journal of Lanzhou University of Technology, 2023, 49(1): 1-6.
[4]	LI Hong-wei, MA Li-na, ZHANG Yan-hui, LI Bo-sheng. Life prediction model of cement-based composite cored wallboard based on Wiener degradation under dry-wet cycles [J]. Journal of Lanzhou University of Technology, 2023, 49(1): 22-29.
[5]	ZHAO Xiao-qiang, LUO Wei-lan, LIANG Hao-peng. Bearing fault diagnosis based on SIR multistage residual connection dense network [J]. Journal of Lanzhou University of Technology, 2022, 48(6): 46-54.
[6]	WANG Yi, YIN Xiang, ZHOU Kai, WANG Xin-min WANG Xin-hua, REN Jun-qiang. Effect of process parameters on microstructure and properties of Ni60-Cu/BaF₂·CaF₂directional structure coating [J]. Journal of Lanzhou University of Technology, 2022, 48(4): 11-18.
[7]	ZHAO Rong-zhen, XUE Yong, WU Yao-chun. Rolling bearing fault data set dimension reduction method of improved D-t-SNE [J]. Journal of Lanzhou University of Technology, 2022, 48(3): 42-49.
[8]	ZHU Qi-xian, LIANG Hao-peng, ZHAO Xiao-qiang, SONG Zhao-yang. Rolling bearing fault diagnosis method based on residual neural network [J]. Journal of Lanzhou University of Technology, 2022, 48(3): 86-93.
[9]	ZHAO Yan-chun, LI Ze-feng, WANG Bo, KOU Sheng-zhong, LI Wen-sheng. Research on mechanical properties of multi-component iron-based amorphous composite [J]. Journal of Lanzhou University of Technology, 2021, 47(6): 1-5.
[10]	LI Ya-min, ZHOU Sheng-rui, HU Wei. Microstructure and properties of K4169 superalloy with nano polycrystalline reinforcement [J]. Journal of Lanzhou University of Technology, 2021, 47(4): 1-5.
[11]	BI Guang-li , CHEN Si-qi, JIANG Jing, LI Yuan-dong ZHANG Yu-sheng, JIANG Chun-hong. Microstructure, mechanical and corrosion properties of an as-extruded Mg-Dy-Ni alloy modified by sliding friction treatment [J]. Journal of Lanzhou University of Technology, 2021, 47(4): 13-21.
[12]	ZHAO Rong-zhen, MA Sen-cai, WU Yao-chun. Fault diagnosis method for rolling bearing based on cloud model and ensemble extreme learning machine [J]. Journal of Lanzhou University of Technology, 2021, 47(4): 33-39.
[13]	YIN Yan, DONG Kai-ji, LI Zhi-heng, BO Yao, LU Chao, ZHANG Rui-hua. Characterization of Fe-Cr alloy powder prepared by close-coupled vacuum induction melting gas atomization [J]. Journal of Lanzhou University of Technology, 2021, 47(3): 10-14.
[14]	ZHAO Yan-chun, WANG Bo, LI Ze-feng, SUN Hao, KOU Sheng-zhong. Study on magnetic properties of Fe-based amorphous composites [J]. Journal of Lanzhou University of Technology, 2021, 47(2): 1-6.
[15]	YAN Chang-feng, ZHAO Wei-kun, MENG Jia-dong, WANG Wen-bin, WU Li-xiao. Defect size estimation of rolling bearings based on double impulses characteristic method [J]. Journal of Lanzhou University of Technology, 2021, 47(2): 39-47.