Electric arc spray process for applying a heat transfer enhancement metallic coating

摘要

A method is disclosed for applying a highly rough thermally conductive metallic coating 1 to a substrate 2 by electric arc spraying an alloy in the form of a feed wire from a group of alloys consisting of Ni-base or Co-base materials. The electric arc spray conditions are selected to produce a sufficiently rough texture to the surface of the coating to enhance the cooling efficiency of the substrate material. The arc spray method provides a coating thickness of between 0.005-0.025 inches with an associated surface roughness average (Ra) of at least 500 microinches. The application of the thermally conductive metallic coating is followed by a heat treatment of the component to improve further the bonding between the coating and the substrate.