Effect of TiO2 nanotubes developed on pure titanium substrates on the mechanical performance of titanium-titanium single-lap adhesive joints

The aim of the present work is to study the combined effect of TiO₂ nanotubes, developed by means of electrochemical anodization on pure titanium adherends, and of the adhesive epoxy resin reinforced with carbon nanotubes (CNTs), on the quasi-static three-point bending behaviour of titanium-titanium single lap adhesive joints. A specific combination of parameters, namely time, type of electrolyte and voltage, has been selected in order to develop nanotubes with optimum geometry in an effort to achieve single lap adhesive joints with enhanced mechanical strength. The mechanical performance of the single lap joints as well as the bonding efficiency of the nano-composite adhesive were studied by means of three point bending and tensile shear tests, while the nano-structural topography was investigated through Scanning Electron Microscopy (SEM) observations. Following the above procedure an increase on the order of 82% in flexural strength for the thus manufactured single-lap adhesive joints was achieved, while the flexural modulus of the joints remained unaffected.