Microstructural Characterization and Mechanical Properties in Friction Stir Welding of Aa7075 Aluminium Alloy

Abstract:

The heat treatable aluminium alloy AA7075 is used extensively in the aircraft industry because of its high strength to weight ratio and good ductility. In this present study the effect of process parameters on the mechanical and micro-structural properties of AA 7075 joints produced by friction stir welding was analyzed. The two sheets, aligned with perpendicular rolling directions, have been welded successively. The welded sheets have been tested under tension at room temperature in order to analyze the mechanical response with respect to the parent materials. Effects of welding speed and fixed location of base metals on microstructures, hardness distributions, and tensile properties of the welded joints were investigated. Optical microscope and SEM analysis revealed that the stir zone contains a mixed structure and onion ring pattern with a periodic change of grain size as well as a heterogeneous distribution of alloying elements. The maximum tensile strength was achieved for the joint produced at rotation speed of 800rpm and a welding speed of 20 mm/s.

• Periodical: Advanced Materials Research (Volumes 622-623)
• Pages: 330-334
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.622-623.330
• Online since: December 2012
• Authors: G. Elatharasan, V.S. Senthil Kumar
• Keywords: AA7075, Aluminium Alloy, Friction Stir, Microstructure

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