Method of surface oxidizing zirconium alloys and resulting product
AssigneeSmith & Nephew, Inc.
InventorsGordon Hunter, Cathrine M. Asgian, Gary L. Hines
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Abstract
An oxide coating is formed on zirconium or zirconium alloys of refined microstructure by a process comprising at least the step of inducing an appropriate altered surface roughness such that subsequent oxidation results in a uniformly thick oxide coating. An oxide coating of uniform and controlled thickness is especially useful on orthopedic implants of zirconium or zirconium-based alloys to provide low friction, highly wear resistant surfaces on artificial joints, such as hip joints, knee joints, elbows, etc. The uniformly thick oxide coating of controlled depth on oxide coated prostheses provides a barrier against implant corrosion caused by ionization of the metal prosthesis.
Claims34
A method of producing an oxide coating on zirconium or zirconium alloy, the zirconium or zirconium alloy having a refined microstructure of a grain size of less than ASTM micro-grain size number 10 and a surface roughness, the method comprising:
- altering said surface roughness of said zirconium or zirconium alloy such that an oxidation process applied to said zirconium or zirconium alloy results in the formation of a uniformly thick oxide coating.
A method of producing an oxide coating of uniform thickness on zirconium or zirconium alloy, the zirconium or zirconium alloy each having a refined microstructure and a surface roughness, the method comprising:
- altering said surface roughness such that an altered surface roughness (Ra) is in the range of about 3 microinches to about 25 microinches prior to subjecting said zirconium or zirconium alloy to an oxidation process.
A prosthesis for implementation in a patient, comprising:
- (a) a prosthesis body having an external surface at least a portion of which is formed of zirconium or zirconium alloy, having a refined microstructure of a grain size of less than ASTM micro-grain size number 10 and an altered surface roughness (Ra) in the range of about 3 microinches to about 25 microinches;
- and
- (b) a zirconium oxide coating of uniform thickness formed on said portion of the external surface by inducing an altered surface roughness on at least said portion of the external surface and subjecting said portion of the external surface of said prosthesis body to an oxidation process.
Dependencies are inferred from the claim text.