Abstract
Friction stir welding is an innovative joining technology that is particularly suitable for aluminium alloys. Various studies have shown a significant dependence of the weld seam quality on the welding speed and the rotational speed of the tool. Frequently, an unsuitable setting of these parameters can be detected by visual examination of resulting surface defects, such as increased flash formation, surface galling, or irregular formation of the surface arc texture. The visual inspection for these defects is often conducted manually and is therefore associated with increased costs and personnel effort. In this work, a method to automatically detect irregularities and features on the weld surface is introduced. It is based on a threedimensional shape detection of the surface features using structured light projection. For this purpose, the topography of EN AW-5754-H111 sheets, welded in a butt joint configuration, was measured. The data were evaluated and characteristic key structures of the weld seam surface were derived. It was shown that welding irregularities can be detected automatically by an evaluation of the weld seam topography. The results are the basis for the future development of an inline quality monitoring and parameter control method for friction stir welding.
Highlights
The annual primary aluminium production has increased from 19.1 million tonnes in 1994 to 60 million tonnes in 2017 [1]
Visual surface inspection The most important surface defects detected during the visual inspection are indicated in figure 3 by differently coloured rings
The most notable surface defects were the occurrence of increased flash formation and surface galling
Summary
The annual primary aluminium production has increased from 19.1 million tonnes in 1994 to 60 million tonnes in 2017 [1]. The main reasons for this trend are the versatile applications and the properties of aluminium alloys, such as the high specific strength compared to other metals [2]. The increasing demand of aluminium alloys in the industry increases the need for suitable processes to join aluminium components. Friction stir welding (FSW) is a solid state welding process, which makes it very suitable for materials that are difficult or impossible to weld by fusion welding processes due to problems with the formation of brittle phases, gas pores and cracking [3]. Friction stir welding has already found applications in various sectors of industry. KAHNERT ET AL. [5] describe the use of FSW for launcher systems at MT Aerospace
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
