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This paper discussed about the consequences of using different filler metal by metal inert gas (MIG) welding process on aluminium alloys Al 7075 sheet metal joint. Nowadays, Al 7075 is widely used in automobile and aviation industry due to its light weight, strong, and high hardness. Fusion welding, such as MIG and TIG were commonly used in joining the aluminium alloys due to its low cost. However, defects usually occurred using fusion welding because of the inaccurate welding parameters and types of filler metal used. The purpose of this study is to determine whether the filler metal with different elements and welding parameters affect the mechanical properties of welded Al 7075. Welding parameters used were current, voltage, welding speed, and Argon (Ar) as shielding gas. Two different types of filler metal were used which is Electrode Rod (ER) 4043 and ER5356 which is from Al-Si and Al-Mg based element, respectively. From microstructure analysis, fusion zone (FZ) of sample welded with ER4043 has a smaller grain size than that of with ER5356. Both filler produced equiaxed den- dritic grain at FZ. Both samples welded with ER4043 and ER5356 has lower hardness value than heat affected zone (HAZ) and base metal (BM) due to the differences in their elements where ER4043 from Al-Si and ER5356 from Al-Mg group. The weld efficiency of sample welded using ER5356 was 61% which was higher compared to sample welded using ER4043 which at 43% and both sample was brittle fractured. Sample welded with ER5356 was fractured at HAZ due to porosity while sample welded with ER4043 fractured at FZ due to the oxide inclusion.
Al 7075, ER4043, ER5356, mechanical properties, microstructure analysis MIG
[1] Fakuda, T., Weldability of 7000 series aluminium alloy materials. Welding International, 26(4), pp. 256–269, 2012. http://dx.doi.org/10.1080/09507116.2011.590665
[2] Tu, J.F. & Paleocrassas, A.G., Fatigue crack fusion in thin-sheet aluminum alloys AA7075-T6 using low-speed fiber laser welding. Journal of Materials Processing Technology, 211, pp. 95–102, 2011. http://dx.doi.org/10.1016/j.jmatprotec.2010.09.001
[3] Stano, S., Pfeifer, T. & Różański, M., Modern technologies of welding aluminium and its alloys. Welding International, 28(2), pp. 91–99, 2014. http://dx.doi.org/10.1080/09507116.2012.708478
[4] Ema, M., Tensile strength of MIG-welded 7000 series aluminium alloy extrusions. Welding International, 22(10), pp. 661–668, 2008. http://dx.doi.org/10.1080/09507110802460895
[5] Budinski, K.G. & Budinski, M.K., Engineering Materials, Properties and Selection, 8th edn., Prentice-Hall, 2005.
[6] Fortain, J.M. & Gadrey, S., How to select a suitable shielding gas to improve the performance of MIG and TIG welding of aluminium alloys. Welding International, 27(12), pp. 936–947, 2013. http://dx.doi.org/10.1080/09507116.2012.753257
[7] Sivashanmugam, M., Manoharan, N., Ananthapadmanaban, D. & Ravi Kumar, S., Investigation of microstructure and mechanical properties of GTAW and GMAW joints of aa7075 aluminum alloy. International Journal on Design and Manufacturing Technologies, 3, pp. 56–62, 2009. http://dx.doi.org/10.18000/ijodam.70063
[8] Miyasaka, F., Okuda, T. & T. Ohji, Effect of current wave-form on AC TIG welding of aluminium alloys. Welding International, 19(5), pp. 370–374, 2005. http://dx.doi.org/10.1533/wint.2005.3437
[9] Temmar, M., Hadji, M., & Sahraoui, T., Effect of post-weld aging treatment on mechanical properties of tungsten inert gas welded low thickness 7075 aluminium alloy joints. Material and Design, 32, pp. 3532–3536, 2011. http://dx.doi.org/10.1016/j.matdes.2011.02.011
[10] Balasubramanian, V., Ravisankar, V. & Madhusudhan Reddy, G., Influences of pulsed current welding and post weld aging treatment on fatigue crack growth behaviour of AA7075 aluminium alloy joints. International Journal of Fatigue, 30, pp. 405–416, 2008. http://dx.doi.org/10.1016/j.ijfatigue.2007.04.012
[11] Ema, M., Tensile strength of MIG-welded aluminium alloys for structures. Welding International, 22(4), pp. 199–205, 2008. http://dx.doi.org/10.1080/09507110802117537
[12] Zhao, P.Z. & Tsuchida, T., Effect of fabrication conditions and Cr, Zr contents on the grain structure of 7075 and 6061 aluminum alloys. Materials Science and Engineering, 499, pp. 78–82, 2009. http://dx.doi.org/10.1016/j.msea.2007.09.094
[13] Cao, X., Wallace, W., Immarigeon, J.P. & Poon, C., Research and progress in laser welding of wrought aluminum alloys. II. metallurgical microstructures, defects, and mechanical properties. Materials and Manufacturing Processes, 18(1), pp. 23–49, 2003. http://dx.doi.org/10.1081/AMP-120017587
[14] Ishak, M., Salleh, M.N.M., Aisha, S.R. & Shah, L.H., The effect of ER 4043 and ER 5356 filler metal on welded Al 7075 by metal inert gas welding. 7th International Conference on Computational Methods and Experiments in Materials Characterisation, 2015.