UK-based composite aerostructures, assemblies and components provider AGC AeroComposites has developed a new, low-cost thermoplastic composite welding technique.

Developed under AGC’s CoFusion project, the new welding technique can be used on both flat and curvature components.

Receiving funding from the National Aerospace Technology Exploitation Programme (NATEP), CoFusion showed that carbon/polyphenylene sulfide (PPS) composite thermoformed components can be welded to produce complex assemblies.

“The CoFusion project was a tremendous opportunity for our company to pursue advances in composite technology."

The process uses resistive composite welding elements that contain no metal meshes or inserts.

The welded components produced by the new technique feature high strength and fatigue properties that have been demonstrated at both coupon and component levels.

Inexpensive equipment and materials can be used in the process, and the heating to welding temperature takes three minutes.

AGC AeroComposites CEO Wayne Exton 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 company noted that the resulting welds possess no voids, thereby passing standard ultrasonic Non-destructive Testing (NDT) specifications.

During the CoFusion project, welded top-hat sandwich panels were produced and structurally compared by torsional strength and fatigue testing to similar riveted parts.

The fatigue performance of the welded component completed 350,000 cycles, while the riveted parts survived 50,000 cycles.

The UK National Composites Centre, TenCate Advanced Composites and Rolls Royce were also involved in CoFusion.

AGC noted half of CoFusion’s £275,000 budget came from NATEP funding for a period of 18 months.

The £40m NATEP technology development programme has been initiated to mature undeveloped aerospace technologies and increase manufacturing jobs in the UK.