Projeção do ferramental para soldagem por fricção de pino rotativo e análise microestrutural do cordão de solda da liga aa1050

Abstract

During the last decades both the aerospace and automobile segments have increased its development, with the main goal on reducing the weight of vehicles, consequently leading to a reduction in fuel consumption, making the development of aluminum alloys as well as the rout processing widely researched. Within this scenario of materials and processes development stand out the aluminum alloys and the friction stir welding process, due to the cost/benefit that they offer. Therefore, the main approach of this research falls within the scope of the analysis of the microstructural properties of the 1050 aluminum alloy submitted to FSW process. Initially, the proper welding parameters were determined and the appropriate tools were designed, consisting of shoulder and pin, machined in VND steel. To study the behavior of the material flow through the threads of the pins, a cylindrical geometry with 1.25 mm, 1.5 mm and 2.0 mm pitches were adopted; factors which were combined with the feed speeds of 5 mm/min and 10 mm/min under the tool rotation speeds of 1800 rpm and 2300 rpm, making it possible to study the influence of FSW welding by stirring the plastically deformed material under this set of parameters. Scanning electron microscopy (SEM) analysis was performed leading to ample evidence on the reliability of the research set. The set corresponding to rotation speed of 2300 rpm, feed speed of 10 mm/min and pin thread pitch of 2.0 mm, presented the best characteristics in visual and SEM analysis, indicating that it is ideal for a weld with good mechanical and microstructural properties, among those studied. However, all samples had different levels of porosity.