Cadmium coatings exhibit an exceptionally good corrosion protection for steel parts. It provides excellent sliding properties with a high corrosion resistance. However, as it is a highly toxic heavy metal identified as hazardous by the REACh regulation (Registration, Evaluation, Authorisation and Restriction of Chemicals) and subject to strict restrictions. Currently, it is only applied on steel parts in aviation industry such as bolts, piston rings or electrical connectors. In addition to that the electroplating process of cadmium implies the risk of hydrogen embrittlement of high strength steels. In the frame of the project Alti2de (Alternative coatings for cadmium and hard chromium with potential for second generation developments), alternatives with similar corrosion protection properties are investigated. Al-Mn-based alloys are deposited on steel substrates by wet or dry deposition techniques. The presentation reports the results obtained from coating development via electrodeposition in ionic liquids, physical and chemical vapor deposition and thermal spraying. The comparison with state-of-the-art cadmium coatings assesses the availability of corrosion resistant alternatives for substitution.
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