Friction wear in metallic contacts without current

Abstract

The wear in electric sliding contacts can have mechanical causes or be produced by electrolysis or chemical corrosion, for instance oxidation or sulfuration. The electric and chemical attack is relatively small in sliding contacts but it may lead to increased roughness of the surfaces that in its turn increases the opportunity for abrasion, which is a mechanical phenomenon. Therefore it will be appropriate to survey the nature of the mechanical friction wear before discussing the influence of the current in § 47. Several major processes of friction wear are distinguished: abrasive or cutting wear, sometimes called scoring; adhesive or galling wear; fretting; and other types, such as surface fatigue.