Friction Stir Weld AA6082-T6 Microstructure and Mechanical Properties Dependence on Tool Design
Posted: 16 Jun 2019
Date Written: May 30, 2019
Abstract
The viability of Friction Stir Welds is dependent upon mechanical properties and production turnovers, which are dependent on welding rates and tool design. This work compares the effect of the standard FSW and the Bobbin tools on the mechanical behaviour of aeronautical alloy AA6082-T6 Friction Stir Welds respectively. The Bobbin tool FSW plates had 70% weld efficiency, better bending strength and ductility; but the standard tool failed prematurely despite having higher static strength, with root bending resulting in cracks, because of alumina rich layers in the onion skin of the weld nugget, and root flaws. The bobbin tool had no root flaw as a result of the additional heating and more intense stirring by the bottom shoulder and lower advance per revolution of the tool. Higher micro-hardnesses in Standard plates compared to Bobbin plate were due to higher advances per revolution, which is known to cause lower heat generation in the weld.
Keywords: Friction Stir Welds; Bobbin Tool; Fracture Mechanism; Mechanical Properties
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