Teaching wet corrosion of metals and alloys

An example of enrichment of the basis practical works with the case of orthodontic steels in artificial saliva

Abstract

To consolidate the knowledge in corrosion acquired by students during courses and theoretic exercises, practical works are highly important. This is already true when the corrosion behavior of pure metals is explored in a broad variety of simple solutions. This can be strengthened further by applying characterizing methods and sense of observation to more complex problems to make a bridge with professional cases that young graduated may be faced with. In the present work, we considered one of the numerous professional situations in which theoretic and practical corrosion teaching may be involved: to anticipate possible long term corrosion for arch wires made of austenitic stainless steel, to be much more aware of the importance of the contents in key elements as chromium, and also to define pertinent protocols for performing tests representative enough. By elaborating a series of model steels with various Cr contents using the specific means of a laboratory of research in materials sciences, and by preparing – in the practical works room – experimental devices and electrolytes to be closest possible to the real conditions of use of arch wires (buccal environment characteristics: human body temperature, complex saliva composition), a supplementary experiment conducted in parallel to the usual series of practical works may also contribute to justify/legitimate further the training in the anticipation of corrosion problems and the possible ways for their limitations.