Silane coupling agent as bridge to assist in preparing high-performance polybutylene terephthalate-aluminum alloy hybrids

Plastic-Metal hybrids have gained significant attention in automotive and aerospace fields. In the study, the silane was introduced on the surface of anodized micro-nano porous aluminum alloy (Al) plate. The silanized Al sample was then joined with polybutylene terephthalate (PBT) specimen by ultrasonic-assisted hot pressing technology to manufacture hybrid. The interfacial physical embedding structure plays an important role in plastic-metal joining and the scanning electron microscope (SEM) results demonstrated that effective mechanical interlocking was achieved between PBT and Al. X-ray Photoelectron Spectroscopy (XPS) results demonstrated the new chemical bonds occurred at the PBT-Al interface, which acted as bridges in the PBT-Al interface joining. Due to synergistic effect of physical embedding and chemical bonding, the maximum adhesion strength reached 36.3 MPa when the silane concentration was 4 %, which was 37 % higher than that without silane treatment. When the silane concentration exceeds 4 %, leading to blocking pores on the anodized aluminum alloy surface, resulting in a decrease in adhesion strength. In conclusion, these results can provide some ideas and help for the development of subsequent plastic-metal hybrids and practical applications.