Análise da influência da ferramenta na qualidade do cordão de solda no processo friction stir welding

Abstract

Friction Stir Welding (FSW), is a recent technology founded in the United Kingdom at the beginning of the 1990s by TWI (The Welding Institute). The process consists of the use of a non-consumable rotary tool. The tool is composed of a pin and a shoulder, when they come in contact with the workpiece, it generates the heat necessary for the mixture, responsible for the joining of the joint. Despite being a relatively new process, FSW has several advantages, such as good mechanical properties and very low environmental impacts when compared to other processes, but the most significant advantage is the performance that friction welding presents when applied in aluminum alloys. For the joint has quality, different welding parameters must be set, such as feed rate, speed of rotation, tool penetration. The choice of values for these parameters should be based on the type of material to be welded, for example for thick plates a higher speed value should be used, since high speed values may cause different joint defects. It is therefore important that the parameter setting is appropriate. This work aims to study the influence of tool geometry and material on the final weld result, designing three different tools, for a later analysis of the results obtained by each one. The results of the study are directed to plates of two millimeters thick of aluminum alloy, showing which geometry is the most appropriate for the execution of the process and also the influence of the nitriding, made in the working tool, in the weld bead.