Techniques for Removing Surface Contaminants in Thin Film Deposition
This paper describes the way to clean bearing surfaces so coatings can be applied to increase wear life. The paper describes the origin of contamination and the techniques of removing them. Typically, bearing surfaces are cleaned in a vapor degreaser consisting of trichlorethylene solvent or by alcohol to remove any oil and grease and then they are pretreated by phosphating, sand blasting, vapor honing, hand polishing, acid etching and electro-etching. Mechanical processes such as sand blasting, vapor honing, and hand polishing cannot be used on a substrate thinner than approximately 0.2 mm, but the acid etching and electro-etching can be used on thin foil substrates and in other specialized applications. In vacuum deposition processes, the surfaces are cleaned in a vacuum prior to deposition so the cleaned surface is not exposed to air before coating and, therefore, the bond is very good.
KeywordsAcid Etching Thin Film Deposition Coating Adherence Thin Oxide Layer Remove Contaminant
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- 2.“A Survey of Contamination — Its Nature, Detection and Control”, Sandia Laboratories Report SC-M-70–303, March 1971.Google Scholar
- 3.S. E. Beal, Thin Solid Films, 53 (1978).Google Scholar
- 4.B. C. Stupp, presented at the Joint Air Force — Navy — Industry Conference on Lubricants, Dayton, Ohio, February 1959.Google Scholar
- 6.H. E. Farnsworth, “Clean Surfaces — The Preparation and Characterization for interfacial Studies”, George Goldfinger, Editor, pp. 77–95, Marcel Dekker, New York, 1970.Google Scholar
- 7.“Heat Treating, Cleaning and Finishing”, Metals Handbook, Vol. 2, American Society for Metals, Metals Park, Ohio, 1964.Google Scholar
- 8.S. F. Murray and S. J. Calabrese, “Selection and Evaluation of Foil Bearing Coatings for Use in Freon-11”, Mechanical Technology Inc., Latham, N.Y., Report, June 1977.Google Scholar
- 10.W. A. Brainard, Proceedings of the 2nd International Conference on Solid Lubrication, pp. 139–147. American Society of Lubrication Engineers, Park Ridge, Illinois, August 1978.Google Scholar
- 11.B. Bhushan and S. Gray, ASLE Trans, (in press) paper presented at ASME/ASLE Joint Lubrication Conference, Minneapolis, Minnesota, October 1978.Google Scholar