Method of simultaneous cleaning and fluxing of aluminum cylinder block bore surfaces for thermal spray coating adhesion
AssigneeFord Global Technologies, LLC
InventorsOludele Olusegun Popoola, Matthew John Zaluzec, Armando Mateo Joaquin, Kimberly A. Lazarz
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Abstract
A method of bonding a thermally sprayed coating to a non-roughened light metal surface. The method comprises the steps of (a) depositing a coating surface (i.e. a double potassium aluminum fluoride salt) onto such surface which has been cleaned to be substantially free of grease and oils. The aqueous deposition provides a protective coating layer to inhibit oxide growth; and (b) subsequently thermally spraying metallic droplets or particles onto the protective coating surface to form a metallic coating that is metallurgically bonded to the cast surface.
Claims8
A method of bonding a thermally sprayed coating to a non-roughened cast light-metal surface substantially devoid of grease and oils, comprising:
- (a) exposing said surface to an aqueous bath containing potassium fluoride, said bath reacting with said surface to form a surface coating of potassium aluminum fluoride salt on said surface to provide a protective coated surface;
- and
- (b) after step (a), thermally spraying metallic droplets or particles onto said coated surface to form a metallic coating that is at least metallurgically bonded to the light-metal surface.
A method of bonding a thermally sprayed coating to a non-roughened cast aluminum based surface substantially devoid of grease and oils, comprising:
- (a) exposing said surface to an aqueous bath at 120-150° F. containing 2-3% KF by weight, said bath reacting with said surface to form a surface coating of a double potassium-aluminum fluoride salt having the phase formula K3AlF6+KAlF3 on said surface to provide a protective coated surface;
- (b) thermally spraying metallic droplets or particles in one stage, whereby said thermally spraying provides droplets or particles of a composite of low carbon steel and FeO to form a top coating;
- and
- (c) honing said top coat to a uniform surface finish of 0.1-1.0 μm and to a thickness of 50-500 micrometers.
A method of bonding a thermally sprayed coating to a non-roughened cast light-metal surface substantially devoid of grease and oils, comprising:
- (a) exposing said surface to an aqueous bath containing potassium fluoride, said bath reacting with said surface to form a surface coating potassium aluminum flouride salt on said surface to provide a protective coated surface, said potassium aluminum fluoride salt being crystalline at 585° C.;
- and
- (b) after step (a), thermally spraying metallic droplets or particles onto said coated surface to form a metallic coating that is at least metallurgically bonded to the light-metal surface.
Dependencies are inferred from the claim text.