Failure Mechanism and Ultimate Strength of Friction Stir Spot Welded Al-5052 Joints under Tensile-shear Loading

Document Type : Original Research Paper

Authors

Mechanical Engineering Department, K.N. Toosi University of Technology, Tehran, Iran.

Abstract

In this paper failure mechanism of a joint which was welded by friction stir spot welding method was studied. The 5052 aluminum joint was loaded under tensile-shear condition.To find out failure mechanism, several tests were conducted such as: strain-stress, macrography, and Vickers hardness. Results of strain-stress test state the stages of failure and crack initiation and propagation. Macrography analysis was done in several stages with different penetration depths. It was shown that the material flow, the critical surface of the coupon, and the determined zones were more possible to generate crack. Finally, by using Vickers hardness test, the susceptible zones to crack generation and propagation can be specified.

Keywords


[1] D. Kim, Resistance spot welding of aluminum alloy sheet 5J32 using SCR type and inverter type power supplie, Mat. Sci. Eng., 38 (2009) 55-60.
[2] L. Han, M. Thornton, M. Shergold, A comparison of the mechanical behaviour of self-piercing riveted and resistance spot welded aluminium sheets for the automotive industry, Mater. Design., 31 (2010) 1457-1467.
[3] A. Gean, Static and fatigue behavior of spot-welded 5182-0 aluminum alloy sheet, Weld. J., 78 (1999) 80-88.
[4] Y. Tozaki, Y. Uematsu, K. Tokaji, Effect of tool geometry on microstructure and static strength in friction stir spot welded aluminium alloys, Int. J. Mach. Tool. Manu., 47 (2007) 2230-2236.
[5] Y. Uematsu, K. Tokaji, Comparison of fatigue behaviour between resistance spot and friction stir spot welded aluminium alloy sheets, Sci. Technol. Weld. Joi., 14 (2009) 62-71.
[6] D. Choi, Formation of intermetallic compounds in Al and Mg alloy interface during friction stir spot welding, Intermetallics, 19 (2011) 125-130.
[7] A. Gerlich, P. Su, T. North, Tool penetration during friction stir spot welding of Al and Mg alloys, J. Mater. Sci., 40 (2005) 6473-6481.
[8] K. Muci-K¨ uchler, S. Kalagara, W.J. Arbegast, Simulation of a refill friction stir spot welding process using a fully coupled thermo-mechanical FEM model. J. Manuf. Sci., 132 (2010) 145-155.
[9] M. Bilici, A.I. Ykler, Influence of tool geometry and process parameters on macrostructure and static strength in friction stir spot welded polyethylene sheets. Mater. Design., 33 (2012) 145-152.
[10] M. Merzoug, Parametric studies of the process of friction spot stir welding of aluminium 6060-T5 alloys. Mater. Design., 31 (2010) 3023-3028.
[11] Y. Yin, A. Ikuta, T. North, Microstructural features and mechanical properties of AM60 and AZ31 friction stir spot welds. Mater. Design., 31 (2010) 4764-4776.
[12] S. Thoppul, R.F. Gibson, Mechanical characterization of spot friction stir welded joints in aluminum alloys by combined experimental/numerical approaches: Part I: Micromechanical studies. Mater. Charact., 60 (2011) 1342-1351.
[13] M. Kurtulmus, Friction stir spot welding parameters for polypropylene sheets. Sci. Res. Essays., 7 (2012) 947-956.
[14] S. Jambhale, S. Kumar, S. Kumar, Effect of process parameters & tool geometries on properties of friction stir spot welds: a review, J. Eng. Sci., 3 (2015) 6-11.
[15] S. Siddharth, T. Senthilkumar, Study of Friction Stir Spot Welding Process and its Parameters for Increasing Strength of Dissimilar Joints, JSA, 5 (2011) 144-150.
[16] W. Yuan, Friction stir spot welding of aluminum alloys, JSA, 1 (2008) 10-18.
[17] D. Klobˇcar, Parametric study of friction stir spot welding of aluminium alloy 5754. Metalurgija, 53 (2014) 21-24.
[18] C. Jonckheere, Fracture and mechanical properties of friction stir spot welds in 6063-T6 aluminum alloy, Int. J. Adv. Manuf. Tech., 62 (2012) 569-575.
[19] G. Buffa, L. Fratini, M. Piacentini, On the influence of tool path in friction stir spot welding of aluminum alloys. J. Mater. Process. Tech., 208 (2008) 309-317.
[20] Q. Yang, Material flow during friction stir spot welding. Mater. Sci. Eng., 527 (2010) 4389-4398.
[21] A. Malafaia, Fatigue behavior of friction stir spot welding and riveted joints in an Al alloy, Proc. Eng., 2 (2010) 1815-1821.
[22] S. Arul, Experimental study of joint performance in spot friction welding of 6111-T4 aluminium alloy, Sci. Technol. Weld. Joi., 13 (2008) 629-637.
23] H. Badarinarayan, Effect of tool geometry on hook formation and static strength of friction stir spot welded aluminum 5754-O sheets, Int. J. Mach. Tool. Manu., 49 (2009) 814-823.
[24] S. Baek, Microstructure and mechanical properties of friction stir spot welded galvanized steel, Mater. T., 51 (2010) 1044-1050.
[25] S. Baek, Structureproperties relations in friction stir spot welded low carbon steel sheets for light weight automobile body, Mater. T., 51 (2010) 399-403.
[26] T. Freeney, S. Sharma, R. Mishra, Effect of welding parameters on properties of 5052 Al friction stir spot welds, SAE Technical Paper, 150 (2008) 171-191.
[27] Z. Zhang, Effect of welding parameters on microstructure and mechanical properties of friction stir spot welded 5052 aluminum alloy, Mater. Design., 32 (2011) 4461-4470.
[28] Y. Tozaki, Y. Uematsu, K. Yokaji. Effect of welding condition on tensile strength of dissimilar friction stir spot welds between different aluminum alloys. in 6th International Symposium on Friction Stir Welding (ISFSW6), Montreal, QC, Canada, Oct. 2006.
[29] F. Hunt, H. Badarinarayan, K. Okamoto, Design of Experiments for Friction Stir Stitch Welding of Aluminum Alloy 6022-T4-Friction Stir Welding of Aluminum for Automotive Applications, SAE Technical Paper, 142 (2006) 84-93.
[30] V. Tran, J. Pan, T. Pan, Effects of processing time on strengths and failure modes of dissimilar spot friction welds between aluminum 5754-O and 7075-T6 sheets. J. Mater. Process. Tech., 209 (2009) 3724-3739.
[31] S. Sato, Characteristics of the kissing-bond in friction stir welded Al alloy 1050. Mat. Sci. Eng., 405 (2005) 333-338.