The research of new assembly technologies for dissimilar materials is growing up continuously mainly for transport application in order to obtain lighter structures and lower energy consumption. The present study proposes a method for laser welding metal having complex properties for the joining process with a polymer. Indeed, high reflective and thin metal plate will be the object of this study.
At the present time, the laser method used for hybrid welding of metal with polymer are based on the use of high powerful lasers for the structuration of the metal plate previous to the joining to the polymer. These lasers are typically in the kW range and CW or long pulsed. This type of laser presents serious limitations when we try to use them in order to structure very thin metal plates or with high reflectivity. Thanks to the use of short and ultra-short pulsing lasers as we propose, we are able to overcome those limitations and achieve very good results. Nanosecond, picosecond and femtosecond laser sources will be studied and compared in the present study.
In this research, we show the method developed following a two steps process and that makes advantage of bio-inspired microtextures. The microtexturation process is followed by a second laser heat up in order to melt the polymer that after filling the textures and cooling down will provide a solid junction.
This complete non-contact laser process allows to avoid the adding of chemical adhesive, assembly elements or additional materials, and gives the possibility to join complex geometries structures while maintaining their integrity.