GKN Aerospace team develops new process to create complex curved structures in titanium

GKN Aerospace - Santa Ana, is now delivering the first production hardware manufactured using an entirely new process that will form compound curves into titanium structures for the first time.

Marcus Bryson, Chief Executive Officer, GKN Aerospace comments: "Our new 'delta pressure forming' process represents an important manufacturing development. It complements our existing titanium manufacturing capability, allowing us to bring the performance benefits of this metal to a great many more severe environment applications across the aero-engine - with resulting improvements in durability and engine weight and reductions in fuel consumption, emissions and noise."

The Company is already successfully using the new process to manufacture the advanced cone-shaped titanium exhaust system for the Boeing 747-800, which commenced delivery early this year. The process will also provide an effective method to create the complex shapes required for extremely rugged items such as engine inlet lips and inner barrels, thrust reverser inner fixed structures and exhaust nozzles and plugs.

Titanium products combine minimal weight with maximum strength and excellent sustained performance in severe environments. GKN Aerospace's established, proprietary, resistance welded and diffusion bonded 'Soundwich R' technology produces flat panels of titanium honeycomb sandwich with excellent noise suppression qualities. Until now, these panels are formed to the shape of the final product using GKN Aerospace's drape creep forming technique. In this process, the flat panel is draped around a die in a vacuum furnace at temperatures well above 1000?F with static weights attached to the ends of the panel. This creates a straight cylindrical or conical shape.

Delta pressure forming starts with the cylindrical honeycomb barrel which has been formed with an improved drape creep forming process that employs a roller system in place of static weights. The cylindrical barrel is inflated into a die to create the required compound curvature. The operation is conducted in a vacuum furnace at temperatures exceeding 1500?F and the inflation pressure is provided by inert argon gas. Sophisticated forming analyses and special tooling features ensure the honeycomb core and the face sheets are not damaged during the process.

Bryson concludes: "The complex and specialised field of titanium manufacture is one of our established areas of expertise and this unique new capability, developed by our highly skilled engineering team, reinforces the technological lead we are proud of and allows us to offer a new level of choice to the aero-engine and airframe primes".