The aim of this activity is to develop a system for connecting pipes using shape-memory alloys (SMAs).

Targeted improvements: to improve AIT and AIV time, to ease connections in deployable appendices.


Shape-memory coupling is a system for connecting pipes using shape-memory alloys. In its typical form the technique uses an internally ribbed sleeve in SMA that is slightly smaller in diameter than the pipes it is connected to. The sleeve is cooled in liquid nitrogen and, in this low-temperature state, mechanically expanded with a mandrel to fit easily over the two pipe ends to be joined. After fitting, it is allowed to rewarm, when the memory effect causes the sleeve to shrink back to its original smaller size, creating a tight joint. It was first produced in the late 1960s or early 1970s by the Raychem Corporation under the trade name CryoFit. Manufacture of these couplings for aerospace hydraulic connections was later transferred to AMCI (Advanced Metal Components Inc.) and then later to Aerofit Products Inc. Additional products using the same shape-memory alloy technology are produced under Cryolive and CryoFlare trade names.

Work logic:

  • Review of the patents and the principles of the actual device produced in the US.
  • Review of all necessary background information concerning cold welding applications for tubes connection.
  • Definition of the potential users main requirement (tube material to be connected, media used in the tubes, application temperature range, sealing, vibration, reliability, AIT constraints, volume, mass, product family range, etc.) for thermal, plasmic propulsion and chemical propulsion applications.
  • Trade-off for the sealing material
  • Trade-off for the shrinking material (Smart Material)
  • Key point: definition of the most important and urgent applications that will be covered by this development
  • Preliminary design including definition of breadboarding and test plan necessary for the materials selection
  • Breadboarding for the materials selection
  • Design detailing using the selected materials
  • Manufacture Breaboard
  • Validation test campaign
  • Lessons learned for the development and recommendations for future activity.


Tender Specifics