Decontaminating aerospace composites
Failure of bonds on titanium and composite materials used for structural components in the aerospace sector can have catastrophic results. Atmospheric pressure plasma jets that generate plasmas at ambient temperature and pressure are increasingly used to remove organic contaminants to increase bond integrity. However, as a relatively new technique, there is currently no available process control technology. EU-funded scientists investigated the feasibility of organic contaminant removal via atmospheric plasma treatments, simultaneously validating appropriate technology for process control. Within the scope of the project 'Surface mapping and control during atmospheric plasma treatments' (PLASMACLEAN), researchers evaluated reflectance infra-red spectroscopy combined with optical emission spectroscopy (OES) and acoustic techniques. Composites were then spray-painted followed by adhesion testing to determine if the plasma-treated surfaces meet requirements for adhesive bonding. The study supported the excellent potential of atmospheric plasma treatment combined with OES for controlled contaminant removal during manufacture of aerospace composites. In addition, the team developed the required surface mapping and control technology to accompany the OES during atmospheric plasma treatment. The OES tool can also identify any thermal damage to the composite caused by the air jet. These advances should lead to real-time process control of an important new technique to enhance the integrity of adhesive bonds. Outcomes are set to have a positive impact on high-end manufacturing industries such as aviation as well as on the safety of large composite structures.
Keywords
Organic contaminant, composite, process control, aerospace, atmospheric plasma, optical emission spectroscopy
