Eventos Anais de eventos
COBEM 2019
25th International Congress of Mechanical Engineering
FRICTION STIR SPOT WELDING OF ALUMINIUM-ALLOY TO STEEL DISSIMILAR OVERLAP JOINTS
Submission Author:
Pedro Paiva Brito , MG , Brazil
Co-Authors:
Erica Schuller, Pedro Paiva Brito
Presenter: Pedro Paiva Brito
doi://10.26678/ABCM.COBEM2019.COB2019-0763
Abstract
The Friction Stir Spot Welding (FSSW) process allows overlapped dissimilar metals to be joined in the solid state, avoiding common complications associated with conventional fusion-based welding processes. In FSSW, a tool in high rotational speed is pressed against the materials to be joined. The friction between the surfaces generates heat and intense plastic deformation, resulting in a metallurgical bond between the sheets. In this paper, an exploratory study was conducted in order to compare mechanical behavior of similar Al-alloy (1200H14) and dissimilar Al-alloy to steel joints (AISI 1020), which were obtained from FSSW process applied in a machining center using Computerized Numerical Control (CNC). Two welding tools were manufactured with difference in shoulder diameter as well as pin diameter and length. The welding operations were performed by applying distinct parameters: rotational speed (from 1000 to 4000 rpm), plunge rate (from 10 to 100 mm/min) and tool dive. The performance of the welded joints was evaluated in terms of tensile strength tests and microstructure characterization. Acquired results shows that FSSW process is practicable in non-specialized equipment, yet sensible to operational parameters. The results showed that in order to obtain mechanically sound dissimilar joints it was necessary apply tool plunge values larger than pin length. Furthermore, the results indicate that shoulder and pin height directly influenced in the effective contact area, impacting on tensile strength of the joints. As a result of the adopted methodology, it was possible to identify optimum operational parameters that conduct to elevated tensile strength of joints.
Keywords
Friction Spot Welding, Aluminum alloys, low carbon steel, Microstructure
