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.

Abstract: A method of defining valve seats on valve seat supports of an internal combustion engine head. The method includes steps of; (a) roughening the exposed surface of the valve seat support to a finish of 10-50 .mu.m RA; (b) thermally spraying a stream of composite particles onto the roughened support surface, using gaseous propellants with sufficient heat and force to produce a dense adherent composite coating of metal and metal oxide particles and to a thickness no greater than 1-1.5 mm; and (c) finish machining if necessary, the sprayed coating to define the valve seat surface. The composite coated product consists of a metal/metal oxide mixture that possesses one or more of the following characteristics: a surface porosity of 2-5%, a density of 6.5-8 grams/cc, a Vickers hardness of about 280 kg/mm.sup.2 at 450.degree. C., high wear resistance and high corrosion resistance.

Abstract: Method of making seat inserts by thermally spraying bulk material. The method includes the steps of: (i) preparing a mandrel having an outside dimension not greater than the desired inside dimension of the desired insert, the mandrel having a part to provide for separation of the sprayed bulk material from the mandrel, (ii) thermal spraying separate particles of one or more types of steel or nickel alloys in the presence of a controlled oxidizing medium to form a bulk composite material on the mandrel with a density of at least 99% and, (iii) after cooling the bulk material, removing such material from the mandrel and slicing it into discrete seat shapes for implanting into the final product.

Abstract: A method of thermally spraying at least one adherent metallic coating onto an unroughened cleansed aluminum or aluminum alloy substrate to produce a coated substrate, comprising: wire-arc thermally spraying of melted metallic bonding droplets and fluxing particles onto the substrate using air propulsion to concurrently adherently deposit flux particles and bonding droplets, the spraying using air propulsion and a wire feedstock having a core and a sheath, the wire core being constituted of both metal powder readily metallurgically bondable to the substrate and a fluxing powder that readily deoxidizes the substrate, the wire sheath being constituted of pliable metal that is metallurgically compatible with the core metal powder, the fluxing powder having a halide salt chemistry effective to deoxidize the substrate upon contact of the melted fluxing powder therewith, said fluxing powder and bonding metal having a particle size that more uniformly promotes distribution throughout said spray.

Abstract: A method of fluxing a cast light-weight metal substrate for thermally adhering sprayed metallic coatings thereto, comprising: (a) preparing the substrate to be clean of grease and oil and to have a uniform and homogeneous surface energy; (b) electrostatically depositing a dry flux powder coating onto such prepared surface; and (c) thermally depositing melted metal onto and across the flux coated surface to further thermally activate the flux if not already activated, for stripping away any substrate oxides and to thermally metallurgically bond the deposited molten metal to the substrate.