Fretting Corrosion of Cu-Ni–Al against Plain Carbon Steel

Abstract

Fretting corrosion of a Cu-Ni-Al alloy against plain carbon steel has been studied in air with 60 per cent relative humidity, nitrogen with 100 p.p.m. oxygen, and silicone oil. As was to be expected on the basis of already existing evidence, the wear in air exceeded that in nitrogen or silicone oil by a factor of 3 to 5. However, contrary to the generally accepted opinion, the high rate of wear in air is not ascribed to the formation of hard abrasive oxides. Instead, the influence of the environment is explained by assuming that in nitrogen with 100 p.p.m. oxygen, and under silicone oil containing dissolved air, an iron oxide with adhesion-reducing properties is formed. The influence of amplitude and frequency has been studied extensively. The observed effects are explained in terms of contact time and deformation of the microwelds.