The effect of titanium surface treatment on the interfacial strength of titanium – Thermoplastic composite joints

Co-consolidated titanium – carbon fibre reinforced thermoplastic composite hybrid joints show potential for application in aerospace structures. The strength of the interface between the titanium and the thermoplastic composite is crucial for the strength of the entire hybrid joint. Application of a surface treatment on the titanium is an effective way to improve this interfacial strength. This paper evaluates the effect of several titanium surface treatments on the interfacial strength between titanium and carbon fibre reinforced polyetheretherketone (PEEK) or polyetherketoneketone (PEKK). Furthermore, the underlying bonding mechanisms, activated by these surface treatments, are studied. The research result shows that the grit blasted titanium – carbon fibre reinforced PEKK interface outperforms the other interfaces.