Influence of temperature and clamping force on the strength of the joint over different composite-metal combinations joined by laser

Vehicle weight in automobile industry is a strict limitation which can be overcome with novel material combinations. Laser conduction joining is an arising alternative but it still poses challenges for joining dissimilar metal-composite materials. Up to now, main research lines have been developed using constant process parameters (laser power and clamping force), so, the behavior of these composite-metal joints under different process parameters, and the control of the process itself, are unknown areas of investigation so far. This paper is focused on the implementation of closed-loop control systems for temperature and clamping force. Tests at different set-points have been carried out for different composite-metal combinations, and the strength of the joints has been assessed by single lap shear tests. The optimal joining process parameters have been found for each material combination.