Effect of surface treatment on the fatigue performance of adhesive/metal interface

Metal surfaces were treated by silane, phosphate and untreated respectively, and then adhered by epoxy resin. The mechanical properties of the adhesive joints by different treatment methods were investigated and the effect of surface treatment on the fatigue performance of the adhesive/metal interface was analyzed. The stress-strain curves of the adhesive joints were compared before and after fatigue load was applied on the joints. Crack propagation in the interface was discussed on the basis of fracture mechanics. The results show that the fatigue resistance of silane-treated samples is the best and the adhesive strength is the greatest. Adhesion failure always initiates at the interface. Energy can release through propagation of crack tips and also can through plastic deformation of the adhesive layer.