New publication on characterization of water-titanium interaction and its effect on adhesion of titanium-C/PEKK joints
Check the latest publication of Vanessa Marinosci on the characterization of the water-titanium interaction and its effect on the adhesion of titanium-C/PEKK joints.
The objective of this paper is to find the root cause of the often-addressed titanium-thermoplastic composite bond instability in the presence of moisture. For this purpose, Atomic Force Microscopy (AFM) experiments were successfully employed for the first time in the context of metal-composite adhesion to investigate the surface interaction between water and the materials considered in this study, namely Ti6Al4V and C/PEKK. The effect of this interaction on the adhesion of co-consolidated Ti6Al4V-C/PEKK joints was evaluated using a mandrel peel test.
This research demonstrates, by combining AFM experiments with mechanical testing, that the Ti6Al4V-C/PEKK adhesion mostly relies on short-range physical interactions, contrary to popular understanding that the metal-polymer adhesion is predominantly governed by mechanical interlocking and/or chemical bonding. Moreover, this research shows that the nature of the native titanium oxide to adsorb water is the primary cause of the adhesion instability. This property of the titanium surface reduces the short-range titanium-PEKK interaction and causes premature failure of the joints in a hot/wet environment.
Therefore, reliable titanium-thermoplastic composite joints for structural applications require a preparation of the titanium surface that aims to prevent or delay water adsorption to guarantee the long-term performance of the joint.
Vanessa has performed this research at the TPRC in close cooperation with the Production Technology research group of Remko Akkerman from the University of Twente.
A special word of thanks goes out to NWO (Dutch Research Council) for financing and supporting this research project.
Overview of the experimental work performed and the main adhesion/degradation mechanisms found in this research.
