The influence of adhesive viscosity and elastic modulus on laser spot weld bonding process

Laser spot weld bonding (LSWB) is a novel joining technology, which combines laser spot welding with a layer of structural adhesive in a single joint. The purpose of this paper is to investigate the effect of the adhesive properties on the joining process, the peel and the shear strength of the LSWB joints. The present work demonstrates that the adhesive viscosity has great influence on the vaporized adhesive gas exhaust process, and the low viscosity is good for the exhaust process. The mechanical test result shows that the tension–shear load of LSWB joint isn׳t always higher than that of the adhesive bonded joint, and LSWB joint with high elastic modulus of adhesive may get the same tension–shear load as the adhesive bonded joint gets. The reaction zone produced by the carbon diffusion between the adhesive and the metal sheet will influence the mechanism of LSWB joint.