Enhanced epoxy adhesion between steel plates by surface treatment and CNT/short-fibre reinforcement

The wettability of grit blasted steel substrates is improved by a simple surface treatment method proposed in this study. The shear strength of epoxy adhesive joints has been improved by over 50% after optimizing this “resin pre-coating” surface treatment method. The shear strength is further enhanced by incorporating multi-walled carbon nanotubes (MWCNTs) and short Kevlar fibres into the adhesive joints, with over 70% improvement for the combined surface-treated and MWCNTs toughened adhesive joints. The reinforcing mechanisms along the “interfacial zone” defined by the surface topography and the toughening mechanisms within the “composite adhesive joints” because of MWCNTs and short Kevlar fibres are discussed together with detailed Scanning Electron Microscopy (SEM) observations and experimental results.