An experimental study on mechanical properties of a novel hybrid metal–polymer joining technology based on a reaction between isocyanate and hydroxyl groups
This study developed a novel joining technology to produce a hybrid polymer–metal material. The technology is based on a reaction between isocyanate groups (NCO) in a solution and hydroxyl groups (OH) on a metal surface. This technology has some advantages compared with other joining methods, such as lack of stress concentration and mechanical and thermal residual stress in the metal structure and very low cost. The effects of different process parameters including the NCO/OH ratio, mould temperature, and polymer melt temperature on the strength of adhesion were investigated employing single lap shear tests. Also, the mechanical behaviour of the hybrid under tensile load was investigated using uniaxial tensile tests. The results showed that increasing mould temperature or melt temperature reduces adhesion strength. Moreover, adhesion strength reaches a peak and then decreases by increasing the NCO/OH ratio. Most importantly, tensile test results showed that the new material postpones the necking phenomena of the stainless steel, and increases the deformation of stainless steel before fracturing by 16%. It is an important result in metal forming that stainless steel can withstand more deformation in its plastic regime.