The main material in detail
Common requirements
One example of the used material can be the follow:
1.) Carbon fibers lying on top of each other all in the same direction.
2.) A resin is added and graphene is also put in the resin.
3.) Sol-gel intermediate layer, e.g. TiO₂/SiO₂
4.) PVD(Physical Vapour Deposition) coating made from Al₂O₃
5.) For Helium tightness add a Parylene-AF4 with a thickness of 5 mikrometer
6.) For lightening protection a aluminium strip can be included or added
Another approach
1.) Using thermal spraying, in this process, the aluminum in the form of wire or powder is fed into a flame or plasma jet, where it is melted and then propelled at high speed onto the surface of the carbon fabric. The molten particles bounce onto the surface, cool and form a solid layer.
2.) Cold gas spraying, Cold gas spraying, on the other hand, uses a carrier gas that accelerates the aluminum powder to a very high speed without melting it. The particles hit the surface with so much kinetic energy that they anchor themselves mechanically and form a dense layer. This process produces very adhesive and low-porosity coatings and can be carried out at lower temperatures than thermal spraying, which is gentle on the base material.
In these two approaches it it also possible to add a PVD layer or a SOl-gel layer.
3.) Graphite foil
It is also possible to add a graphite foil to create a helium tightness. This graphite foil can be attached with an adhesive.
4.) Add graphene to carbon fibre
There are several possibilities to add graphene to carbon fibers to create a helium tightness.
The approved methods are, using a
spray or dip coating with binder
or
electrophoretic deposition (EPD)
or
pyrolytic carbon coating.
In a first analysis the electropheretic deposition would be the best solution
Fixed and flexible material
The material must be flexible or fix, to create a fix version, the numbers of the fibers must be increased and the line of the carbon fibers must be changed.