Research Project Develops New Composite Welding Technique

AGC AeroComposites, a supplier of composite aerospace assemblies has developed a new Innovative thermoplastic composite welding technique.

The company has recently completed their “CoFusion” project with funding from the National Aerospace Technology Exploitation Programme (NATEP), in partnership with the UK National Composites Centre, TenCate Advanced Composites and Rolls Royce. The project involved work to optimise the efficiency and applicability of an innovative, low-cost thermoplastic composite welding process.

The “CoFusion” project demonstrated that carbon/polyphenylene sulfide (PPS) composite thermoformed components can be reliably welded to form complex assemblies utilising resistive composite welding elements that contain no metal meshes or inserts.

The resulting welded components feature consistent high strength and fatigue properties that have been demonstrated at both coupon and component levels. Low cost equipment and materials can be used and the heating to welding temperature takes only three minutes. The process is not limited to flat components; panels with significant curvature can be welded reliably. All resulting welds are high quality with no voids passing standard ultrasonic Non-destructive Testing (NDT) specifications.

Welded top-hat sandwich panels were produced and structurally compared by torsional strength and fatigue testing to identical riveted parts. The welded component had higher stiffness and greater strength reaching five times that of the riveted component. The fatigue performance of the welded component was also significantly superior with no damage at 350,000 cycles in comparison to the riveted parts that only survived 50,000 cycles.

Wayne Exton, CEO of AGC AeroComposites said;

The CoFusion project was a tremendous opportunity for our company to pursue advances in composite technology, the ability to weld thermoformed thermoplastic composite components to form structurally efficient light weight assemblies allows us to continue to provide our global customer base with innovative, high quality, cost-effective products.

The NATEP funding ran for 18 months and had a total budget of £275,000; half of which was funded through NATEP