Effect of ultrasonic-assisted on the bonding properties of hot-pressing molded polybutylene terephthalate/aluminum alloy composite

The mechanical properties and structure of polybutylene terephthalate (PBT)/aluminum (Al) composite prepared by ultrasonic-assisted hot-pressing were analyzed, and the influence of ultrasonic-assisted on the bonding properties of PBT/Al composite was studied. The experimental results showed that under the optimal ultrasonic-assisted conditions, the tensile shear strength of the PBT/Al composite reached 26.55 MPa, which was 22.18% higher than that of the PBT/Al composite without ultrasonic-assisted (21.73 MPa). Scanning electron microscopy (SEM) showed that during the hot-pressing process, ultrasonic-assisted promoted the embedding of PBT in the anodic oxide pores on the surface of Al, forming a stronger mechanical interlocking structure. X-ray diffraction (XRD) showed that ultrasonic-assisted did not change the crystal type of PBT, but the shear effect of ultrasound affected the arrangement and orientation of molecular chains in the PBT melt, resulting in changes in crystallinity. X-ray photoelectron spectroscopy (XPS) showed that ultrasonic-assisted did not generate new chemical bonds during the hot-pressing process. Therefore, during the hot-pressing process, ultrasonic-assisted promoted the embedding of PBT in the anodic oxide pores on the surface of Al, enhanced the mechanical interlocking effect between PBT and Al, and improved the tensile shear strength of the PBT/Al composite.