Abstract
Conventional arc welding processes are difficult to use to join thin sheet magnesium alloy because of the necessity of high energy input, which in turn leads to various problems such as burn through and distortion. Alternatively, laser welding can resolve these problems because of lower heat input and smaller spot size compared to conventional welding. Even when using laser welding, it is difficult to weld thin magnesium sheets with a thickness of less than 1 mm; cut, melt through and cracks tend to occur due to the evaporation of molten metal and high solidification rate. In this study, an attempt has been made to lap fillet welding of thin sheet magnesium alloy AZ31B with a thickness of 0.3 mm using a pulsed Nd:YAG laser beam in a conduction mode. This paper investigates the occurrence of defects in the lap fillet joint of AZ31B magnesium alloys. Defects such as void and cracks were observed at the weld root. A void at the root occurred because of lack of fusion due to insufficient melting of the lower sheet. The void was reduced by grinding the metal surface to eliminate the oxide layer. Cracks generated in large grain areas initiated from the void at the root. A higher scan speed significantly improves the defect behaviour because of generating a narrow large grain area and wider fine grain area. Macropore-free weld was obtained in this laser welding research, and smaller amount of micropores than the base metal can be attained.
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References
Moon, J., Katayama, S., Mizutani, M., Matsunawa, A.: Lap welding characteristics of thin sheet metals with combined laser beams of different length. Jpn. Weld Soc. 20, 468–476 (2002). (In Japanese)
Shizuo, U., Taisuke, A., Kanichiiro, S.: The welding conditions of very thin aluminum sheet of high welding. Jpn. Weld Soc. 11, 361–364 (1993)
Leong, K.H., Sabo, K.R., Altshuller, B., Wilkinson, T.L., et al.: Laser beam welding of 5182 Aluminum alloy sheet. J. Las. A 11(3), 109–118 (1999)
Aghios, E., Bronfiu, B., Eliezer, D.: The role of the magnesium industry in protecting the environment. J. Mater. Process Tech. 117, 381–385 (2001)
Jinhong, Z., Lin, L., Zhu, L.: CO2 and diode laser welding of AZ31 magnesium alloy. Appl. Surf. Sci. 247, 300–306 (2005)
Toshikatsu, A., Hiroshi, T., Hitaka, I., et al.: Some characteristics of pulsed YAG laser welds of Magnesium Alloys. Nihon University research report no 38, 1–9 (2005)
Lung, K.P., Che, C.W., Ying, C.H., et al.: Optimization of Nd:YAG Laser welding onto magnesium alloy via Taguchi analysis. Opt. Laser Technol. 37, 33–42 (2004)
Ghazanfar, A., Lin, L., Uzma, G., Zhu, L.: Effect of high power diode laser surface melting on wear resistance of magnesium alloys. Wear 260, 175–180 (2006)
Quan, Y.J., Chen, Z.H., Gong, X.S., et al.: Effects of heat input on microstructure and tensile properties of laser welded magnesium alloy AZ31. Mater. Charact. 59(10), 1491–1497 (2008)
Rihar, G., Uran, M.: Lack of fusion-Characterisation of indications. Weld World 50(½), 35–39 (2006)
Abe, N., Tsukamoto, M., Morikawa, A., et al.: Welding of aluminum alloy with high power direct diode laser. Trans. JWRI 31(2), 157–163 (2002)
Barsoum, Z., Lundback, A.: Simplified FE welding simulation of fillet welds-3D effects on the formation residual stresses. Eng. Fail. Anal. (2009). doi:10.1016/j.engfailanal.03018
Barsoum Z, Jonsson, B.: Fatigue assessment and LEFM analysis of cruciform joint fabricated with different welding processes. Inter Inst Welding Doc.no XIII-2175-07 (2007)
Teng-Shih, S., Jyun-Bo, L., Pai-Sheng, W.: Oxide films on magnesium and magnesium alloys. Mater. Chem. Phys. 104, 497–504 (2007)
Zhou, W., Long, T.Z., Mark, C.K.: Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D. Mat Sci and Tech 23(11), 1294–1299 (2007)
Munitz, A., Cotler, C., Stern, A., et al.: Mechanical properties of gas tungsten arc welded magnesium AZ91D plates. Mat. Sci. Eng A 302, 68–73 (2001)
Mahadzir, I., Yamasaki, K., Maekawa, K.: Lap fillet welding of thin sheet AZ31B magnesium alloy with pulsed Nd:YAG laser. J. Int. A Solids Mechanics 3(9), 1045–1056 (2009)
Pastor, M., Zhao, H., Martukanitz, R.P. et al.: Porosity, underfill and magnesium loss during continuous wave Nd:YAG laser welding of thin plates of aluminum alloy 5182 and 5754. Weld Res. Supp 207–216s (1999)
Cao, X., Jahazi, M., Immarigeon, J.P., Wallace, W.: (2006) A review of laser welding techniques for magnesium alloys. J. Mat. Process. Tech. 171, 188–204
Zhao, H., Debroy, T.: Pore formation during laser beam welding of die-cast magnesium alloy AM60b —mechanism and remedy. Weld Res Supp 204–210s (2001)
Jun, S., Guoqiang, Y., Siyuan, L., Fusheng, P.: Abnormal macropores formation during double-sided gas tungsten arc welding of magnesium AZ91D alloy. Mat. Charact. 59, 1059–1065 (2008)
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Ishak, M., Yamasaki, K., Maekawa, K. (2013). Characteristics of Welded Thin Sheet AZ31 Magnesium Alloy. In: Öchsner, A., Altenbach, H. (eds) Experimental and Numerical Investigation of Advanced Materials and Structures. Advanced Structured Materials, vol 41. Springer, Cham. https://doi.org/10.1007/978-3-319-00506-5_9
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DOI: https://doi.org/10.1007/978-3-319-00506-5_9
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