Résistance à la corrosion d’alliages cuivreux utilisés en connectique

Corrosion resistance of some copper alloys commonly used in connectics

¹ Sté Souriau, Service Matériaux et Procédés, la Ferté Bernard
² Laboratoire de Corrosion et Traitements de Surface - Université de Franche-Comté - Besançon.

Abstract

For connectics applications, selection of an alloy takes into account the feasibility of protective coatings (such as gold, nickel, tin... etc), as well as their physical and mechanical properties.

The hight cost of gold, for instance, has led to selective deposits, the thickness of which has been continuously decreasing ; thus, the influence of the substrate has become an important factor for the corrosion resistance of the connectors.

The selection of a corrosion resistant alloy will improve the behaviour of the protected part.

In this respect, some copper and/or nickel alloys have been tested for corrosion, by H₂S alone and by a mixture H₂S + SO₂.

They also have been studied through electro-chemistry, in aqueous solutions of sodium sulfide, in order to compare their behaviour in this medium and in agressive atmosphere.

The follow-up of corrosion, whatever the process, has been carried out through electro-chemical reduction curves, and completed using physico-chemical techniques such as X-ray diffraction, EDX, and XPS.