A New Method for Etching Surfaces of Bearings and Other Machine Elements

Abstract

The method relates to the production of shallow recesses in surfaces by etching. Recesses in metal surfaces are particularly suitable for use in sliding bearings for rotating components and in some other machine elements. Frequently, such recesses have a depth of 10 microns or more and are made in the form of intricate groove patterns on curved surfaces. According to the new method, etching fluid is caused to flow by means of a flow guiding template onto areas determined by this template along the surface to be etched. The etching rate on the areas to be etched is controlled by adjustment of the flow velocity of the etching fluid and the slit height of the flow guiding template. The recesses or grooves are deeper when the flow velocity of the etching fluid and the slit height are both higher. The paper gives a brief description of the new etching method and a comparison with other fabrication methods such as photochemical etching and electro-chemical machining. The new method appears to be preferable to others for large series production. The paper concludes with theoretical work in which the etching process is explained in terms of mass transfer by connective diffusion and with some experimental results using a simplified flow guiding template design.