Dynamic melt pool behaviour during laser transmission welding of thermoplastics

Abstract

Experimental knowledge regarding the fluid dynamical processes in laser transmission welding of thermoplastics and their influences to the resulting welding zone has not been acquired until now. Therefore, investigations concerning the on-line visualisation of the melting pool behaviour are carried out using a system of high-speed microfocusradioscopy. With systematic variation of process parameters, the dynamic melt pool behaviour in the welding zone of the polymeric parts is detected. The evaluation of the flow conditions during laser transmission welding shows clearly the influence of the welding strategy (contour and quasi-simultaneous welding) as well as the effect of laser and material parameters. The results can be used for increasing process speeds and optimising the mechanical properties of the weld. This paper presents, apart from the analysis equipment, results of the dynamic melt pool behaviour during laser transmission welding of thermoplasticsExperimental knowledge regarding the fluid dynamical processes in laser transmission welding of thermoplastics and their influences to the resulting welding zone has not been acquired until now. Therefore, investigations concerning the on-line visualisation of the melting pool behaviour are carried out using a system of high-speed microfocusradioscopy. With systematic variation of process parameters, the dynamic melt pool behaviour in the welding zone of the polymeric parts is detected. The evaluation of the flow conditions during laser transmission welding shows clearly the influence of the welding strategy (contour and quasi-simultaneous welding) as well as the effect of laser and material parameters. The results can be used for increasing process speeds and optimising the mechanical properties of the weld. This paper presents, apart from the analysis equipment, results of the dynamic melt pool behaviour during laser transmission welding of thermoplastics