Tapered double cantilever beam test used as a practical adhesion test for metal/adhesive/metal systems

To quantify the practical adhesion between an epoxy-amine adhesive (DGEBA + IPD) and a titanium alloy (Ti6Al4V), a tapered double cantilever beam (TDCB) test was used. The critical strain energy release rate (G(Ic)) was evaluated. An appropriate size of the sample allows the fracture to propagate within the adhesive/metal interfacial region. The crosshead speed, the joint thickness, and the adhesive formulation all influence the experimental results. For low crosshead displacement speeds (< 1 mm min(-1)), the crack speed was controlled by the crosshead displacement. For higher crosshead displacement speeds, the crack propagation was controlled by the interfacial region critical strain energy release rate. By adding a reactive liquid rubber (ETBN 13) to the initial adhesive formulation, an increase in the critical strain energy release rate was observed.