Abstract
Heat conduction joining is mainly used in laser-based joining of metals with polymers but results in a large amount of dissipated heat. The consideration of thermal efficiency allows the determination of power actually used for creating the joint, which is highly relevant for technical and economic reasons, e.g., for calculating the carbon footprint. In order to describe the thermal efficiency universally, process parameters (focal diameter, joining speed, energy per unit length), metallic materials (AA 6082, AISI 304), geometric parameters (overlap width, material thickness) and various polymers (polypropylene, polyamide 6, polyamide 6.6) were examined experimentally. The discussion of the results is supplemented by numerical simulations of the temperature field. For a general description of the physical relationships, some dimensionless numbers based on the Buckingham π theorem were developed, applied to the experimental data. One of these numbers shows similarity to the Fourier number and provides further information on thermal efficiency and its general understanding in the context of polymer–metal joints, enabling the physical background dissipated to stored heat.
Highlights
Polymer–metal hybrid composites are gaining importance in several fields of application and the motivation for this is manifold
The overlap was kept constant at 75 mm, which meant that the joining partners overlapped completely
It should be noted that no process window was reached for a focal diameter of 1.7 mm in these tests. This can be explained using aluminium at 2 mm sheet thickness as an example: at 0.35 m·min−1, deep penetration welding occurs after a certain seam length; at 0.40 m·min−1, heat conduction welding occurs, and at 0.45 m·min−1, an insufficient molten zone width below 3 mm is reached
Summary
Polymer–metal hybrid composites are gaining importance in several fields of application and the motivation for this is manifold. The lightweight potential of such composites can be exploited in novel constructions, e.g., in the automotive or aviation industries. There are different joining approaches for different material groups to realize polymer–metal composites. In addition to mechanical joining processes [1] and adhesive bonding [2], thermal direct joining has great potential for application in thermoplastic–metal hybrid joints [3]. By saving on auxiliary joining elements such as screws or rivets and on filler materials such as adhesives, a direct bond between polymer and metal can be created [4]. Laser beams have great advantages over alternative processes due to the non-contact energy input and the high degree of flexibility with regard to the components to be manufactured [7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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 callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
