In the recent years, use of composites has been developed to reduce the weight of the structure. One type of composites is hybrid of polymer-metal. This new material allows properties of both materials to be used in one piece simultaneously. In this research, reaction between isocyanate and hydroxyl groups was used for joining polyamide6 to stainless steel. The bond strength between metal and polymer is one of the most important features in polymer-metal hybrid. So, effect of parameters such as ratio between isocyanate and hydroxyl groups, polymer melt temperature and mold temperature on bond strength is investigated through single shear lap test. Moreover, tensile and bending test samples were fabricated based on maximum bond strength. The results show that bond strength decreases by increasing mold temperature or polymer melt temperature and reaches to a peak then lower by raising proportion of the isocyanate and hydroxyl groups. Furthermore, hybrid behavior in the tensile test shows that polymer postponed phenomenon of necking in metal. Created warpage in the hybrid specimen removed from the mold and also its behavior in three point bending test were simulated using Abaqus and Moldflow softwares. Flow analysis is carried out on the polymer layer in Moldflow, then to conduct the subsequent thermo-mechanical analysis of the residual-stress development and hybrid warping, the following results obtained using Moldflow were passed to Abaqus. The hybrid specimen is cooled to room temperature with viscoelastic properties and three point bending is carried out after considering warpage effect on the hybrid. Viscoelastic properties were obtained from stress relaxation tests and the contact between two layers of metal and polymer was defined as cohesive surface. The cohesive surface parameters are obtained from simulation and experimental test. The results illustrated that there is a good agreement between simulation and experimental warpage as well as between bending modulus obtained from experimental and simulation. Keywords: Polymer to metal adhesion, TDI, Polyol, Cohesive contact, Viscoelastic, injection molding
