Metal-polymer direct joining: effect of polymer injection speed on joint strength

摘要

This work experimentally investigates the effect of injection speed on the joint strength of metal-polymer direct joining. The joint products were processed by the Injection Molded Direct Joining (IMDJ) method. In IMDJ, micro/nano structures are formed on metal surfaces prior to injection molding process to join metal and polymer directly. In this work, we focused on two parameters: size of metal surface structures and polymer injection speed. We used two different chemical etching methods to form different structures. Using treated metal pieces, we processed joint products under different injection speed conditions and measured the joint shear strength. The tensile test results show that the effects of injection speed are different according to the surface structure size. We discuss this difference from the viewpoint of the replication ratio, the viscosity and the viscous resistance of melted polymer.