Modification of Ti-6Al-4V plates with Schiff base complex and adhesive performance of Ti-6Al-4V/PEEK

The adhesion between a metal alloy and a polymer is the problem focus of fiber metal laminates (FMLs) utilization. In this study, the Schiff base complex was firstly tentatively utilized for the surface modification of Ti-6Al-4V (TC4), in order for a bridge between TC4 and PEEK to be built. In addition, the TC4 plates were anodized for the synergistic effects between roughness and complex to be explored. Differently modified TC4 plate surfaces were analyzed through Fourier Transform Infrared Spectroscopy (FT-IR), Thermogravimetry/Differential Scanning Calorimetry (TG/DSC), Contact angle measurements (CA), Scanning Electron Microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Atomic force microscopy (AFM). Moreover, the adhesive strength was studied through single lap shear testing. It was evidenced that the Schiff base and the corresponding complex were successfully synthesized; furthermore, the complex was loaded on the TC4 plate surface through self-assembly. When the TC4 plates were anodized and loaded the Schiff base complex, single lap shear strength significantly increased, reaching to 47.49 MPa. This was a 53.89% growth compared to the anodized TC4 plate strengths. It was demonstrated that the Schiff base complex highly contributed to the adhesive strength through the multiple effects of coordination, hydrogen bonding interactions, mechanical interlocking and molecular entanglement. (C) 2018 Elsevier Ltd. All rights reserved.