Composite article and method

• US 8,262,814 B2
• Filed: 11/17/2008
• Issued: 09/11/2012
• Est. Priority Date: 11/16/2007
• Status: Active Grant

• Current Assignee: Richemont International SA (Compagnie Financiere Richemont SA)
• Original Assignee: Gad Zak
• Inventors: Zak, Gad
• Primary Examiner(s): Silverman, Stanley
• Assistant Examiner(s): Walck, Brian
• Application Number:
  US12/272,675
• Publication Number:
  US 20090199932A1
• Time in Patent Office: 1,394 Days
• Field of Search: 148/281, 148/421, 148669-672, 420/417, 420/422
• US Class Current: 148/281
• CPC Class Codes: B22D 25/026 Casting jewelry articles B22D13/063 takes precedence
• CPC Class Codes: C22C 14/00 Alloys based on titanium
• CPC Class Codes: C22C 16/00 Alloys based on zirconium
• CPC Class Codes: C23C 8/02 Pretreatment of the material to be coated C23C8/04 takes precedence
• CPC Class Codes: C23C 8/10 Oxidising
• CPC Class Codes: C23C 8/80 After-treatment
• CPC Class Codes: Y10T 428/13 Hollow or container type article [e.g., tube, vase, etc.]
• CPC Class Codes: Y10T 428/31678 Of metal

Abstract

Method, and articles therefrom, for providing a hard, abrasion-resistant, attractive, oxide surface layer of selectable thickness and having an outer appearance within the scale from gray to blackness, to a zirconium titanium alloy article by heating the article in an oxygen containing atmosphere.

Claims

1. A method for producing an article having a darkened surface, the method consisting of the steps of:

providing an article made from an alloy consisting of between about 18.4% and about 65.6% of zirconium by atomic weight and titanium;

heating the article in an oxygen containing atmosphere at a temperature of between about 250 and about 880 degrees Celsius for a period between about 10 and about 110 minutes;

the heating step includes a first heating step, a quenching step following the first heating step, and a second heating step.

2. The method of claim 1, in which said first heating step is performed at a lower temperature than said second heating step.

3. The method of claim 2, in which the first heating step is carried out at a temperature of between about 250 and about 480 degrees Celsius for between about 10 and about 40 minutes.

4. The method of claim 2, in which the second heating step is carried out at a temperature of between about 480 and about 880 degrees Celsius for between about 10 and about 70 minutes.

5. The method of claim 1, in which the alloy contains between about 34.4% and about 65.6% zirconium by atomic weight.

6. The method according to claim 1, in which said oxygen containing atmosphere is air.

7. The method according to claim 1, in which the article is a machined, cast, or die-forged article.

8. The method according to claim 1, wherein the darkened surface has a matte or satin finish.

9. The method according to claim 1, wherein the darkened surface includes a gray black color.