Design and durability of titanium adhesive joints for marine applications

摘要

Comparative measurements of strength and Griffith's critical strain energy release rate G_(Ic) were carried out on adhesively bonded joints with different surface treatments of titanium, before and along 13 weeks of accelerated aging in salted or deionized water at 50 °C. Thermo-mechanical measurements were carried out on the bulk epoxy adhesive, with the same aging conditions. A combined surface treatment of sanding, degreasing and chemical etching showed the best durability, whereas a treatment using an additional sulphuric anodic oxidation showed the best adhesion before aging. Aging decreased the strength and the critical strain energy release rate of bonded joints by 30-70%. Joint design with a finite element calculation using a cohesive failure law at the interface, accounting for surface treatment, aging effects and safety factors, can thus be performed, from a limited set of experimental values.