Abstract

There is an increasing interest in the use of multi-materials in the transport sector in order to reduce the weight of vehicles and the  fuel consumption for a clean mobility towards the goal of zero CO2 emissions, as defined the European directive (EU) 2019/1161.

The use of hybrid materials has promoted the research on dissimilar joints (metal-polymer) in order to solve the drawbacks related to the traditional joining techniques such as stress concentration, large repairs area and emissions harmful to the environment.

In this work, the behavior of hybrid joints between steel and GRFC with thermoplastic matrix by laser technology has been analyzed. This study is framed to the European project RECOTRANS, focused on the manufacturing of composites (RTM and pultrusion) with new MW accelerated curing acrylic resins and their joining to metal inserts using LAMP technology (laser assisted metal polymer joining).

Laser technology for metal-polymer joining is an alternative to other conventional processes offering relevant advantages over these techniques since it is a single-stage instantaneous automated process, with localized heating and low residual stresses.

In this study, the shear behavior of laser assisted joints between AISI304 steel samples and composites with different acrylic resin formulations has been analyzed. The effect that different variables have on these joints has been evaluated, such as the topography of the metallic surface, the temperature generated during the joining process or the laser interaction time. The results obtained show a mechanical resistance similar or even higher than that obtained in adhesive joining.