CFD Numerical Model Development for Friction Stir Welding of Aluminum Alloys
Luciano Buglioni1; Leonardo Tufaro1; Hernán Svoboda2
1 Instituto Nacional de Tecnología Industrial; 2 GTSyCM3-INTECIN-FIUBA y CONICET
doi:10.20906/CPS/CILAMCE2015-0284
Resumo
Friction Stir Welding (FSW) is a solid state welding process which has strongly impacted aluminum structural elements fabrication, specifically for aeronautical, aerospace, shipbuilding and automotive industry, among others. FSW uses a tool consisting of a shoulder and a pin which is inserted into the joint and moves along it to produce the welding. Heat is generated between the tool and material leading to a plastically deformed region surrounding the FSW tool. Numerical models of friction stir welding are of great interest due to the complexity of the involved phenomena and the difficulty to measure different process magnitudes. They can be formulated by different approaches: from single thermal models, to coupled ones solving either thermal and elastic equations by finite element formulations; or CFD (computational fluid dynamics) models which include both Navier-Stokes and thermal equations. CFD models are have as input parameters thermal material properties, slip between tool and workpiece, welding rotation and travel speeds, tool position and heat dissipation parameters from working plate boundaries. As a result can be seen thermal fields, in addition with thermal fluxes, specifically contributions as much from sticking as from sliding of the tool-workpiece interaction. Other results include tool axial force and stirring zones, by analyzing strain rates and velocity fields. Nevertheless, several aspects of the process are still under discussion as heat dissipation to the backing plate, thermal fields around the tool, pressure distribution under the tool, etc. The present work a CFD based numerical FSW model was developed and thermal fields in conjunction with axial force and fluid patterns were analyzed and contrasted to experimental measurements. In order to achieve this aim, samples of AA5083 plates of 3 mm thick were welded by FSW, with different travelling speed and tool rotational velocity. During the welding both plate temperatures at different distances from the weld centerline and tool axial force w
Palavras-chave: FSW; CFD; Welding temperatures