Avaliação da união produzida pelo método de soldagem a fricção e mistura mecânica em uma junta topo de liga AA6060-T5

Abstract

The low weldability of certain materials gave rise to the so-called friction stir welding process in the 1990s. It is able to perform the solid state bonding by means of a special geometry tool that in contact with the components promotes the intensive mixing of the material and the adhesion mechanism of the surfaces. The parameters of the process are directly related to the dimensions and compositions of the materials to be joined, and due to this, many studies are carried out to determine the ideal parameters. In this context, the objective of this work is to carry out the process in a 6060-T5 aluminum alloy of 4.75 mm thickness in the top joint configuration, through the adaptation in a vertical machining center provided by the Federal University of Pampa. The welds were run at feed rates of 30 mm/min and 50 mm/min at three different speeds, 1000, 1500 and 2000 rpm. The results obtained through visual inspection, metallographic analysis, microhardness and tensile tests showed that the combination of 50 mm/min and 1500 rpm presented the most reliable results. The rotational speed of 2000 rpm did not contribute to increased mechanical strength and produced cavities in the welded region for the two levels of feed velocity. Due to the higher heat input the welds with lower feed speed presented less resistance. Even so, the parameter window adopted in this work can be considered good, since the joint efficiency obtained was always higher than 80%.