Effect of metal micro-structuring on the mechanical behavior of polymer-metal laser T-joints

The metal was locally structured by pulsed laser radiation producing microscopic patterns on its surface. In a second step the opposite side of the micro-structured metal was irradiated by a continuous wave (CW) fiber laser to achieve the mechanical interlock between the two materials. A tight relationship between the microstructure parameters and pull-out test performance was observed. The greatest strength was achieved when the distance between subsequent grooves was minimized. The T-joint mechanical performance did not reveal any significant dependence on the considered range of joining areas. The morphological and topographical features of the detached surfaces showed that the micro-structured grooves were completely filled during the laser conductive joining process. Different alignment angles of patterns produced different failure modes although there was no evidence of an additional mechanical interlock.