Estudo preliminar de soldagem através do processo friction stir welding de uma junta sobreposta dissimilar das ligas alumínio 6060 t5 e cobre c110 com duplo recuo

Abstract

The welding solid state FSW (Friction Stir Welding) is a process developed primarily for application in aluminum alloys with low weldability. Recently, studies focused on the use of this method when joining together dissimilar materials, demonstrated the versatility of this process to obtain metallurgical bonds between metals with different properties. The phenomena of chemical bonds involved in the FSW method caused by the temperature elevation by mechanical friction and mixing plastic materials, results in the application of FSW in basically all materials that have sufficient ductility. The present work consists in implementing the FSW process in the union between the following dissimilar materials: Aluminum 6060 T5 and C110 Copper, in which we study the performance of a proposed tool translation system called "double recoil", comparing it with the conventional system to evaluate its benefits. The double recoil system correspondent welding actions, where the tool starts and ends welding, conducting a 2mm retreat in the oposite direction. As for the conventional system, the tool penetrates, moves and returns. To enable this study, we made a concise literature review which it approaches the main elements in friction welding, as well as the parameters and settings used in welding by the specialists. The methodology is characterized as applied in nature of the search, explanatory as to the purposes and experimental in the procedures. The welds are performed by applying one of four ratios of rotation (800, 900, 1000 and 1100 rpm) in both translation systems, and the results evaluated on the basis of visual observation of the samples, doing tensile tests, verifying of macrographs and trials of microhardness along the weld beads. After analyzing the results, it was noticed that the welding using the rotation parameter 900 rpm under the conventional system of translation, showed the highest reliability in the results of monotonic traction. The retreats were not effective under the metallurgical point of view, leaving voids in the reworked areas. Even so it follows that all the parameters varied in this work, independently of the system, are consistent of a good welding window, allowing sustainably welding Al / Cu materials excluding any third element ( ex .: pin, screw , etc.) commonly used.