Stress-corrosion behavior and characteristics of the friction stir welding of an AA2198-T34 alloy

Abstract

To better understand the stress-corrosion behavior of friction stir welding (FSW), the effects of the microstructure on the stress-corrosion behavior of the FSW in a 2198-T34 aluminum alloy were investigated. The experimental results show that the low-angle grain boundary (LABs) of the stir zone (SZ) of FSW is significantly less than that of heated affected zone (HAZ), thermo-mechanically affected zone (TMAZ), and parent materials (PM), but the grain boundary precipitates (GBPs) T1 (Al₂CuLi) were less, which has a slight effect on the stress corrosion. The dislocation density in SZ was greater than that in other regions. The residual stress in SZ was +67 MPa, which is greater than that in the TMAZ. The residual stress in the HAZ and PM is −8 MPa and −32 MPa, respectively, and both compressive stresses. The corrosion potential in SZ is obviously less than that in other regions. However, micro-cracks were formed in the SZ at low strain rate, which indicates that the grain boundary characters and GBPs have no significant effect on the crack initiation in the stress-corrosion process of the AA2198-T34. Nevertheless, the residual tensile stress has significant effect on the crack initiation during the stress-corrosion process.

Keywords

slow strain rate test / residual stress / grain boundary characteristic / AA2198-T34 alloy / friction stir welding

References

[1] Cavaliere P, Cabibbo M, Panella F, Squillace A. 2198 Al-Li plates joined by Friction Stir Welding: Mechanical and microstructural behavior. Mater. Des., 2009, 30(9): 3622.

[2] Guérin M, Alexis J, Andrieu E, Blanc C, Odemer G. Corrosion-fatigue lifetime of Aluminium-Copper-Lithium alloy 2050 in chloride solution. Mater. Des., 2015, 87, 681.

[3] Bolivar J, Frégonèse M, Réthoré J, Duret-Thual C, Combrade P. Evaluation of multiple stress corrosion crack interactions by in-situ Digital Image Correlation. Corros. Sci., 2017, 128, 120.

[4] Zhu LK, Yan Y, Li JX, Qiao LJ, Li ZC, Volinsky AA. Stress corrosion cracking at low loads: Surface slip and crystallographic analysis. Corros. Sci., 2015, 100, 619.

[5] Lavigne O, Gamboa E, Luzin V, Law M, Giuliani M, Costin W. The effect of the crystallographic texture on intergranular stress corrosion crack paths. Mater. Sci. Eng. A, 2014, 618, 305.

[6] Goebel J, Ghidini T, Graham AJ. Stress-corrosion cracking characterisation of the advanced aerospace Al-Li 2099-T86 alloy. Mater. Sci. Eng. A, 2016, 673, 16.

[7] Chen SY, Li JY, Hu GY, Chen KH, Huang LP. Effect of Zn/Mg ratios on SCC, electrochemical corrosion properties and microstructure of Al-Zn-Mg alloy. J. Alloys Compd., 2018, 757, 259.

[8] Meng CY, Zhang D, Zhuang LZ, Zhang JS. Correlations between stress corrosion cracking, grain boundary precipitates and Zn content of Al-Mg-Zn alloys. J. Alloys Compd., 2016, 655, 178.

[9] Donatus U, Ferreira RO, Mogili NVV, Viveiros BVGD, Milagre MX, Costa I. Corrosion and anodizing behaviour of friction stir weldment of AA2198-T851 Al-Cu-Li alloy. Mater. Chem. Phys., 2018, 219, 493.

[10] Milagre MX, Donatus U, Mogli NV, Sliva RMP, de Viveiros BVG, Pereira VF, Antunes RA, Machado CSC, Araujo JVS, Costa I. Galvanic and asymmetry effects on the local electrochemical behavior of the 2098-T351 alloy welded by friction stir welding. J. Mater. Sci. Technol., 2020, 45, 162.

[11] Donatus U, Viveiros BVGD, Alencar MCD, Ferreira RO, Milagre MX, Costa I. Correlation between corrosion resistance, anodic hydrogen evolution and microhardness in friction stir weldment of AA2198 alloy. Mater. Charact., 2018, 144, 99.

[12] Xu WF, Liu JH, Zhu HQ. Analysis of residual stresses in thick aluminum friction stir welded butt joints. Mater. Des., 2011, 32(4): 2000.

[13] Huang JL, Li JF, Liu DY, Zhang RF, Chen YL, Zhang XH, Ma PC, Gupta RK, Birbilis N. Correlation of intergranular corrosion behaviour with microstructure in Al-Cu-Li alloy. Corros. Sci., 2018, 139, 215.

[14] Dhondt M, Aubert I, Saintier N, Olive JM. Effects of microstructure and local mechanical fields on intergranular stress corrosion cracking of a friction stir welded aluminum-copper-lithium 2050 nugget. Corros. Sci., 2014, 86, 123.

[15] Medjahed A, Henniche A, Derradji M, Yu TF, Wang Y, Wu RZ, Hou LG, Zhang JH, Li XL, Zhang ML. Effects of Cu/Mg ratio on the microstructure, mechanical and corrosion properties of Al-Li-Cu-Mg-X alloys. Mater. Sci. Eng. A, 2018, 718, 241.

[16] Luo C, Albu SP, Zhou XR, Sun ZH, Zhang XY, Tang ZH, Thompson GE. Continuous and discontinuous localized corrosion of a 2xxx aluminium-copper-lithium alloy in sodium chloride solution. J. Alloys Compd., 2016, 658, 61.

[17] Qin HL, Zhang H, Wu HQ. The evolution of precipitation and microstructure in friction stir welded 2195-T8 Al-Li alloy. Mater. Sci. Eng. A, 2015, 626, 322.

[18] Milagre MX, Mogili NV, Donatus U, Giorjão RAR, Terada M, Araujo JVS, Machado CSC, Costa I. On the microstructure characterization of the AA2098-T351 alloy welded by FSW. Mater. Charact., 2018, 140, 233.

[19] Robe H, Zedan Y, Chen JQ, Monajati H, Feulvarch E, Bocher P. Microstructural and mechanical characterization of a dissimilar friction stir welded butt joint made of AA2024-T3 and AA2198-T3. Mater. Charact., 2015, 110, 242.

[20] Guérin M, Andrieu E, Odemer G, Alexis J, Blanc C. Effect of varying conditions of exposure to an aggressive medium on the corrosion behavior of the 2050 Al-Cu-Li alloy. Corros. Sci., 2014, 85, 455.

[21] Chen S, Jiang X. Texture evolution and deformation mechanism in friction stir welding of 2219Al. Mater. Sci. Eng. A, 2014, 612, 267.

[22] Liu JH, Zhao K, Yu M, Li SM. Effect of surface abrasion on pitting corrosion of Al-Li alloy. Corros. Sci., 2018, 138, 75.

[23] Ma Y, Zhou X, Huang W, Thompson GE, Zhang X, Luo C, Sun Z. Localized corrosion in AA2099-T83 aluminum-lithium alloy: The role of intermetallic particles. Mater. Chem. Phys., 2015, 161, 201.

[24] Wang JT, Zhang YK, Chen JF, Zhou JY, Ge MZ, Lu YL, Li XL. Effects of laser shock peening on stress corrosion behavior of 7075 aluminum alloy laser welded joints. Mater. Sci. Eng. A, 2015, 647, 7.

[25] Zhang XX, Zhou XR, Hashimoto T, Liu B, Luo C, Sun ZH, Tang ZH, Lu F, Ma YL. Corrosion behaviour of 2A97-T6 Al-Cu-Li alloy: The influence of non-uniform precipitation. Corros. Sci., 2018, 132, 1.

[26] Proton V, Alexis J, Andrieu E, Delfosse J, Lafont MC, Blanc C. Characterisation and understanding of the corrosion behaviour of the nugget in a 2050 aluminium alloy Friction Stir Welding joint. Corros. Sci., 2013, 73, 130.

[27] Bononi M, Conte M, Giovanardi R, Bozza A. Hard anodizing of AA2099-T8 aluminum-lithium-copper alloy: Influence of electric cycle, electrolytic bath composition and temperature. Surf. Coat. Technol., 2017, 325, 627.