The manufacture of space propellant tanks could be brought back to Britain following an ESA-funded project investigating the best way of making tank parts at close to net shape.
During the two-year project Strathclyde University’s Advanced Forming Research Centre (AFRC) will use its expertise in forming and forging to advise Airbus Defence and Space – which buys its fuel tanks from Germany or the US – on advanced manufacturing methods for the tanks.
Dr Jill Miscandlon, project leader at AFRC, said: “A tank is generally made of two hemispherical domes and a cylindrical section. The parts are forged, heat-treated and machined down to the required final thickness before they are welded together. They are very thin structures and machining them down from the original thickness results in significant material waste, in addition to the high cost of the machining.
“Over the past four months, we’ve been looking at methods of achieving near net-shape manufacture, at the same time maintaining the material properties because in space it has to be structurally sound.
“The tanks must be strong enough to store propellant, such as Hydrazine or Xenon gas, under high pressure during a mission’s lifetime, which could be more than 25 years. At the same time, for some un-controlled re-entry LEO (Low Earth Orbit) satellite platforms, upon return, they should vaporize upon meeting the upper atmosphere so not to present a risk to people and facilities on Earth.”
The AFRC and Airbus DS are bringing in welding research organisation TWI to help decide the chosen method for producing the tanks. Currently in phase one, the AFRC is advising on the best processes for making efficient parts for the propellant tanks.
Dr Miscandlon said: “Airbus DS will merge their own research experience with our study and decide on the chosen technique to take forward. This could be metal forming, superplastic forming or additive manufacturing processes – all of which would produce the tank parts at close to net shape.
“Key to the project is making components in a shorter lead-time and wasting less expensive material, which is essential with titanium alloys costing up to $60 per kilo, depending on alloy type and manufacturing route. We are also focused on sharing the project outputs with the wider supply chain here in the UK.”