EFFECT OF TOOL ROTATIONAL AND WELDING SPEED ON MECHANICAL AND MICROSTRUCTURAL CHARATERISTICS OF FRICTION STIR WELDED AZ31B MAGNESIUM ALLOY JOINTS
Keywords:
magnesium alloy, microstructure, tensile propertiesAbstract
In recent times, the greater attention on welding of magnesium alloys has been growing rapidly in aerospace and automotive industries due to their excellent properties such as light weight, high specific strength and stiffness. Fusion welding of these alloys is not preferable due to hot cracking, formation of porosity etc. However solid state welding techniques, such as, friction sitr welding are found to offer solution to the above problems. In this study, an attempt was made to understand the effect of welding speed of FSW process on microstructure and tensile properties of AZ31B magnesium alloy. Fabrication of FSW joints were completed using different levels of tool rotational between 1400 rpm and 1800rpm and for different welding speed between 0.4 mm/sec and 0.6 mm/sec. Tensile properties of the welded joints were evaluated and correlated with the weld zone microstructure and hardness. From this investigation, it is found that the joints fabricated using a tool rotational speed of 1600 rpm, welding speed of 0.5 mm/sec and an axial force of 4 kN yielded superior tensile properties compared to other joints. Formation of finer grains and higher hardness in stir zone are the main reasons for the superior tensile properties of these joints.
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References
Edgar R L (2000), “Magnesium Alloys and their Application”, K.U. Kainer Publication, France.
Kojima Y (2000), “Handbook advanced magnesium technology”, Kallos Publishing Co., Ltd., Tokyo.
Patzies C and Kainer K U (2004), “Fatigue of magnesium alloys”, Adv. Eng. Mater., Vol.6, 281-289.
Wang Xunhonga and Wang Kuaishe (2006), “Microstructure and properties of friction stir butt-welded AZ31 magnesium alloy”, Materials Science and Engineering A, Vol. 431, 114-117.
Afrin N, Chen D L, Cao X and Jahazi M (2008), “Microstructure and tensile properties of friction stir welded AZ31B magnesium alloy”, Materials Science and Engineering A, Vol. 472, 179-186.
Cao X and Jahazi M (2009), “Effect of Welding Speed on the Quality of Friction Stir Welded Butt Joints of a Magnesium Alloy”, Materials and Design, Vol. 30, 2033– 2042.
Padmanaban G and Balasubramanian V (2010), “Fatigue performance of pulsed current gas tungsten arc, friction stir and laser beam welded AZ31B magnesium alloy joints”, Materials and Design, Vol. 31, 3724-3732.
Rajakumar S, Balasubramanian V and Razalrose A (2013), “Friction stir and pulsed current gas metal arc welding of AZ61A magnesium alloy: A comparative study”, Materials and Design, Vol. 49, 267-278.
Buffa G, Hua J, Shivpuri R and Fratini L (2006), “Design of the friction stir welding tool using the continuum based FEM model”, Material Science and Engineering A, Vol. 419, 389-396.
Wang Xunhonga and Wang Kuaishe (2006), “Microstructure and properties of friction stir butt-welded AZ31 magnesium alloy”, Materials Science and Engineering A, Vol. 431, 114-117.
Hassan A A, Norman A F and Prangnell P B (2002), “The effect of the welding conditions on the nugget zone in friction stir welds in an AA7010 alloy”, Sixth International Trends in Welding Research Conference Proceedings, 287- 292.
Liu H J, Fujii H and Maeda M (2003), “Tensile properties and fracture locations of friction stir welded joints of 2017- T351 aluminium alloy”, Journal of Material Processing and Technology, Vol. 142, 692-696.
Lomolino S, Tovo R and Dos Santos J (2005), “On the fatigue behaviour and design curves of friction stir butt welded Al alloys”, International Journal of Fatigue, Vol. 27, 305-316.
Lee W B, Kim J W, Yeon Y M, Jung S B (2003), “The Joint Characteristics of Friction Stir Welded AZ91D Magnesium Alloy”, Material Transaction, Vol. 44, 917-923.
