Contact angle and wettability of hybrid surface treated metal adherends

Abstract

Adhesion performance of adhesively bonded metal joints was much dependent on the surface treatment of the adherends. This work was aimed at optimizing the hybrid surface treatment, a combination of mechanical, chemical, and energetic surface treatment methods to improve wettability of metal surfaces and strength of adhesive metal joints. The surface free energies and wettability of hybrid surface treated metal adherends were measured for different treatment conditions with grit blast, sulfuric acid etching, silane treatment, and flame treatment. The surface morphology and chemical composition were investigated by SEM (Scanning electron microscopy) and XPS (X-ray photoelectron spectroscopy) and the bond strengths of the single-lap joints composed of aluminum and stainless steel foils were measured with respect to surface treatment conditions. From the experiments, an effective hybrid surface treatment condition was suggested for metal surfaces with super-hydrophilic characteristics. Also, the failure mode of adhesive metal joints was evaluated by the photo-surface analysis method.