Bearing assembly and the like for use in corrosive and non-corrosive atmospheres

This invention relates to a novel machine element characterized by mutually rubbing surfaces which are composed of dissimilar materials having high hardness, a low coefficient of friction, and resistance to corrosion by halogen-containing atmospheres. As exemplified by the preferred embodiment for use in gaseous UF6, the rubbing surfaces are chemically deposited nickel and anodized aluminum. These surfaces permit jam-free operation despite long-term exposure to UF6. Preferably, both surfaces have a hardness of at least about 500 HV100 on the Vickers hardness scale, and preferably the anodized-aluminum surface is of type having comparatively little tendency to sorb uranium hexafluoride