Magnetic Pulse Joining of Metallic/Metallic and Metallic/Non-Metallic Material Combinations for Space Applications

Many Spacecraft parts are manufactured from high melting point materials such as Titanium or steel (e.g. propellant tanks which are manufactured using Ti-6Al-4V and welded using either TIG or Election Beam),. Recently the ESA Directive “Design for Demise” has been introduced, which states: “What goes up must completely burn up – or ‘ablate’ – during uncontrolled atmospheric re-entry as a means of post-mission disposal”. Therefore there is a danger that for some components which are manufactured from high temperature materials, they might survive re-entry. The trend is therefore to replace such materials with lower melting point materials such as aluminium. However other smaller parts such as pipework, tubing and support are still likely to be made from materials such as Titanium. There is therefore a need to develop new joining techniques which can enable metals of different melting point to be fabricated. In addition, more CFRP structures are also being introduced into spacecraft. There is also a need to address the joining of metallic parts to non-metallic parts for various applications.

In the current programme, the technique of Magnetic Pulse Joining (MPJ) is being developed which has the capability to join aluminium to titanium as well as Metallic parts to non-metallic parts such as CFRP. In this presentation, the development of the MPJ technology will be described and will highlight the need to accurately control the delivery of the magnetic pulse, coupled with an efficient trigger mechanism and coil design. Two joint configurations are currently being developed, an Al-Ti port-to-tube interface for a propellant tank, and an Al-CFRP strut.