Reference : Acoustic-Emission-Analysis of Dissimilar Laser-welds of Aluminium and Polyamide 6.6
Scientific journals : Article
Engineering, computing & technology : Materials science & engineering
Physics and Materials Science
http://hdl.handle.net/10993/36430
Acoustic-Emission-Analysis of Dissimilar Laser-welds of Aluminium and Polyamide 6.6
English
Schiry, Marc mailto [University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Engineering Research Unit >]
Lamberti, Christian mailto [University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Engineering Research Unit >]
Böhm, Peter mailto [University of Applied Science Trier]
Plapper, Peter mailto [University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Engineering Research Unit >]
2016
Universal Journal of Materials Science
4
6
119-124
Yes
International
2331-6691
2331-6705
[en] Acoustic-Sound-Emission ; Laser Beam Welding ; Aluminium ; Polyamide 6.6 ; Non-destructive Testing
[en] A novel laser joining process for hybrid polymer-metal structures has proven a strong bond between polyamide and aluminium. This welding technique is strongly requested by the automobile producing industry for numerous applications within structure components. However, the joining quality exhibits a strong dependency on process-related variables, which highlights the need for an online inspection technique. The requirements for a chosen inspection technique are [1], [2]: 1. Showing the results on-line during the joining process; 2. Working non-destructive; 3. Working as an integral method; Being able to determine weld defects. In that case only the Acoustic Emission Analysis (AEA) as a Non-Destructive-Technique (NDT) can be used to guarantee reasonable results. During the first tests at the welding laboratory at the Laser Technology Competence Centre (LTCC) at the University of Luxembourg, AEA sensors are applied onto the surface of the test specimen which has to be welded. In this principle acoustic events, caused by welding defects, are recorded during the laser joining. The most important laser process parameters, like velocity, power and horizontal focal position of the laser spot, have been verified and evaluated by the AEA. It was observed that insufficient laser power can lead to the break of the melting bath, which is often not recognizable by non-destructive optical methods [2]. The AEA however was able to detect this lack of fusion. Using high laser power, the appearance of gas bubbles arising from the Polyamide 6.6 could be detected afterwards in a microscopic micrograph. The AEA signals related to this effect can be correlated clearly. Due to the high pressure of the gas bubbles, the aluminium weld is often interrupted, which can be traced back to the solidification of the aluminium molten mass. Due to the actual situation, the AEA is a well-working NDT online monitoring method and can be used for the correlation of acoustic events and welding defects within the mentioned joining method. Future tasks will develop some algorithms to separate the different defects by pattern recognition of the AEA signals and parameter
http://hdl.handle.net/10993/36430
http://www.hrpub.org/journals/article_info.php?aid=5383

File(s) associated to this reference

Fulltext file(s):

FileCommentaryVersionSizeAccess
Limited access
Acoustic-Emission-Analysis of Dissimilar Laser-welds of Aluminium and Polyamide 6.6.pdfAuthor postprint503.87 kBRequest a copy

Bookmark and Share SFX Query

All documents in ORBilu are protected by a user license.