Rocket-Science?

Although its not rocket-science it has the potential to make things easier in the Thermosphere and above. The talk is about Plasma Metal Deposition (PMD) for space applications.

Because space is an uncomfortable place it is essential to use materials with high toughness, one of those is titanium. Due its excellent corrosion resistance compared with its specific strength it is a superior material for such applications. One of its drawbacks is its high price and that’s the point where PMD is entering the game.

With its near-net-shape manufacturing style, titanium parts can be made with much less material than traditional machining methods like milling or lathing resulting in a more economic production.

Repair welding of turbine parts

Repair welding of worn off turbine parts like casings, rings, gaskets.

With the ASTRA – the automated system for turbine repair application – turbine parts can be overhauled by hardfacing respectively build-up by plasma welding.

The constricted plasma arc suits perfectly for such tasks. Due to offering a high energy density at low amperage, the plasma welding process is predestinated for repair welding of filigree structures i.e. thin edges.

Joint welding of satellite propellant tank

Satellite propellant tanks are often made of titanium due two reasons.
First titanium offers a great specific strength and second it has good corrosion resistance.

Lifting a mass of 1kg into the orbit is not a bargain - starting at 2,500€ and rising up to several 10,000€ depending on the orbit height. To save weight and therefore money for the rocket start, propellant tanks of satellites are made of thin titanium sheets with a thickness between 0.8-1.2mm. This thin titanium skin acts as a tight membrane. To withstand the enormous pressure resulting due the gauge pressure and the evacuated space, the titanium membrane is wrapped by carbon or glass fibre reinforced plastic layers.

The welding of the titanium sheets can be done by Plasma Welding with or without a filler wire. Argon, which is used for shielding gas, trailing gas and forming gas, protects the liquid weld pool during the Plasma Welding process from atmospheric conditions and keeps the seam safe and clean.

Welding of tanks for wine storage and transportation

In the processing & handling of beverages, stainless steels are the favoured materials to use. Thanks to their good durability against corrosion and their low affinity to release alloying elements, stainless steels are a superb choice for this task. Plasma Spot Welding is used to join stainless steels in an economic way, the focused plasma arc and the additional shielding gas enable fast and safe welding procedures.