Cobalt chrome coated titanium implant

Patent metadata

Field	Value
Publication number	US-9370605-B2
Application number	US-201313783894-A
Country	US
Kind code	B2
Filing date	Mar 4, 2013
Priority date	Mar 4, 2013
Publication date	Jun 21, 2016
Grant date	Jun 21, 2016

Abstract

A method for coating an orthopedic implant made of a titanium or titanium alloy substrate with a cobalt-chrome molybdenum alloy uses multi-arc physical vapor deposition (MA-PVD). The substrate has a first bearing surface coated with a coating made of the deposited cobalt-chromium molybdenum alloy. The bearing surface slidably receives a second bearing surface of the prosthetic joint component. The MA-PVD cobalt-chromium molybdenum alloy coating forming the first bearing surface is made up of hexagonal close packed (HCP) grains having a columnar structure with a length of about 1 μm and a width of about 0.1 μm with the length of each HCP grains being oriented generally perpendicular to the titanium substrate bearing surface.

First claim

The invention claimed is:

1. A method for manufacturing a prosthetic implant comprising:
providing a substrate comprising titanium;
coating a surface of the substrate with a cobalt-chromium molybdenum alloy by multi-arc physical vapor deposition to produce a majority of grains having a hexagonal close pack (HCP) phase, the cobalt-chrome molybdenum alloy comprising about 66 weight percent cobalt, 27.9 weight percent chromium, and about 5.1 weight percent molybdenum; and
polishing the cobalt-chromium molybdenum HCP coating.

2. The method as set forth in claim 1 wherein the grain sizes are between 0.1 and 1.0 μm.

3. The method as set forth in claim 1 wherein the substrate is a commercially pure titanium or a titanium alloy.

4. The method as set forth in claim 1 wherein the HCP grains have a columnar grain structure wherein the grains have a length which is perpendicular to the substrate surface.

5. The method as set forth in claim 4 wherein the columnar grains are about 1 μm long and 0.1 nm wide.

6. The method as set forth in claim 1 wherein the polishing is performed by a polishing process selected from the group consisting of a media polishing process, a sequential grade SiC wheel grinding an Al 2 O 3 slump polishing process and a soft wheel polishing process.

7. The method as set forth in claim 6 wherein the surface roughness is Ra<50 nm after polishing.

8. The method as set forth in claim 6 wherein the surface roughness is Ra<25 nm.

9. The method as set forth in claim 1 wherein the polished cobalt-chrome HCP coating has a hardness greater than 500 Vickers Diamond Pyramid Hardness (DPH) at a 25 g load.

10. The method as set forth in claim 1 wherein the coating is greater than 30% chromium plus molybdenum.

11. The method as set forth in claim 1 wherein the cobalt-chrome molybdenum alloy coating is between 6 and 100 μ00 m before polishing.

12. The method Os set forth in claim 11 wherein the cobalt-chrome molybdenum alloy coating is between 5 and 95 μm thick after polishing.

Assignees

• Howmedica Osteonics Corp

Inventors

• Zhang Zongtao
• Hanson Keenan Michael
• Mccarthy Thomas Francis
• Lawrynowicz Daniel E
• Wang Aiguo

Classifications

• A61F2/3094

  Designing or manufacturing processes · CPC title

• A61F2/30767

  Special external or bone-contacting surface, e.g. coating for improving bone ingrowth · CPC title

• A61F2310/00023

  Titanium or titanium-based alloys, e.g. Ti-Ni alloys · CPC title

• A61L2420/02

  Methods for coating medical devices · CPC title

• C23C14/16

  on metallic substrates or on substrates of boron or silicon · CPC title