Improvement in Mechanical and Metallurgical Properties of Friction Stir Welded 6061-T6 Aluminum Alloys through Cryogenic Treatment

Abstract:

An investigation has been made to improve the properties of the friction stir welded (FSW) 6061-T6 aluminum alloys. A cryogenic thermal treatment is developed for the joints during welding and its effects on mechanical and metallurgical properties, and precipitates are evaluated at various welding parameters. The friction stir welded joints with cryogenic treatment attained the better properties than the without cryogenic treatment. The improvement of properties was attributed to the refinement of grain size and to the introduction of a reduction in the softening region of the welded joints. Under cryogenic cooling rates, joints were experienced to the low temperature environments and faster cooling rates, which are contributed to enhance the hardness of the stir zone and heat affected zone regions and the formation of fine grain structure in the stir zone. The results indicated that the formation of finer grains of less than 5 µm in the stir zone, which is smaller than the joints of without cryogenic treatment. Subsequently, mechanical properties drastically improved and the joints achieved a maximum joint efficiency of 74% of the base material

• Periodical: Materials Science Forum (Volume 969)
• Pages: 490-495
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.969.490
• Online since: August 2019
• Authors: K. Tejonadha Babu, S. Muthukumaran*, C.H. Bharat Kumar, C. Sathiya Narayanan
• Keywords: Aluminum Alloy, Cryogenic Treatment, Friction Stir Welding, Grain Refinement, Mechanical Properties

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