Method for making metallic surface layer for heat transfer augmentation

摘要

An article comprising a substrate and an outer metallic layer, such as a coating, is provided with augmented heat transfer from the substrate through the combination of a layer thickness of about 0.003'' to about 0.017'', a layer surface roughness of at least about 500 micro inches Ra, a layer tensile bond strength of at least about 5 ksi, and a heat transfer augmentation of at least about 1.1. A method of making the article uses an electric arc wire thermal spray process in which the atomizing gas pressure is maintained within the range of about 20-80 psi.