Vacuum Cadmium

The pure cadmium is vaporized in a vacuum chamber and condenses on the surface of the components. The coating that is created with this technology has a powdery top layer and is overall very soft.

Compared to galvanic applied coatings it is a more open structured coating and in direct comparison not as adherent and rigid.

The process makes hydrogen embrittlement technically impossible which is a big advantage when it comes to high strength steels e.g springs and landing gear components.

Cadmium has a long history as coating material mainly due to its excellent corrosion protection properties, its self healing capabilities, electrical conductivity and lubrication properties.

Nevertheless, Cadmium is listed as a Substance of very high Concern by the ECHA and REACh. Alternatives are hard to find and only the IVD – Aluminium is qualified today to take over some of the applications.

The awareness of a missing full scale substitute for cadmium leaves the use of cadmium restricted to only a few applications such as aerospace or high risk components.
Aero-Coating GmbH implemented a full awareness program to use and work with Cadmium under the highest safety standards.

Main application of the vacuum cadmium technology (French: Cadmiage sous vide) used by Aero-Coating GmbH is the coating of high strength steels which are vulnerable to hydrogen embrittlement.

The hydrogen embrittlement is a process on atomic level which blocks the dislocation movements of the metallic structure.

This causes a drop in toughness and increases the probability of cracking from static or dynamic loads.

The dry process under vacuum prohibits the introduction of hydrogen to the parts and hydrogen embrittlement is therefore technically impossible.

Advantages

• No hydrogen embrittlement
• High anti contact corrosion protection
• High protection against atmospheric and galvanic protection
• Very good lubricating properties
• Service temperature of max. 200°C
• Electrical conductive

Environmental

• Environmental friendly substitute: IVD–Aluminium
• hexavalent Chromate free conversion coatings are under investigation

Substrates

• High strength steel

Application

Aerospace sector

• landing gear components
• Springs
• Bolts and nuts
• Retaining rings

Please contact us for further information.