Wear resistant component and process therefor
A method for providing a wear-resistant component includes depositing an aluminum coating on a steel component to provide an aluminum-coated steel component, and subjecting the aluminum-coated steel component to a plasma electrolytic oxidation (PEO) process. The PEO process converts a surface portion of the aluminum coating to alumina. A wear-resistant component includes a steel component and a wear-resistant coating on the steel component. The wear-resistant coating includes an alumina surface portion and an underlying portion of either aluminum or aluminum and nickel combination or nickel aluminide that contacts the steel component.
1 . A method comprising:
depositing a nickel coating onto a steel component;
depositing an aluminum coating onto the nickel coating to provide an aluminum-nickel-coated steel component;
heat-treating the aluminum-nickel-coated steel component to form a diffusion zone of nickel aluminide, an overlying portion of the aluminum coating remaining as aluminum after the heat-treating; and
subjecting the aluminum-nickel-coated steel component to a plasma electrolytic oxidation (PEO) process, the PEO process converting a surface portion of the overlying portion of the aluminum coating to alumina, an underlying portion of the aluminum coating remaining as aluminum after the PEO process.
2 . The method as recited in claim 1 , wherein the heat-treating is conducted in a protective atmosphere of argon, nitrogen or vacuum in a temperature range of 500° C. to 800° C.
3 . The method as recited in claim 1 further comprising a machining process to attain a surface finishing of Ra 4 to 50 after the heat treatment prior to the PEO process.
4 . The method as recited in claim 1 , wherein the depositing of at least one of the aluminum coating or the nickel coating is conducted by at least one of physical vapor deposition, cold spray, friction stir manufacturing, thermal packing aluminizing, or electrodeposition in a non-aqueous solution.
5 . The method as recited in claim 1 , further comprising, prior to the depositing the nickel coating, degreasing and etching a surface of the steel component onto which the aluminum coating is to be deposited.
6 . The method as recited in claim 1 , further comprising, after the depositing the aluminum coating and before the PEO process, machining the aluminum coating to a desired coating thickness of 10 to 100 micrometers and a surface finish of Ra 4 to 50.
7 . The method as recited in claim 1 , further comprising sealing the alumina with a sealant to prevent corrosion, including impregnating the alumina with PTFE or non-chromate corrosion inhibitors.
8 . The method as recited in claim 1 , further comprising applying a lubricious material to the alumina.
9 . The method as recited in claim 1 , wherein the steel component is a shaft.