Nickel Coating

• US 20080124542A1
• Filed: 11/26/2007
• Published: 05/29/2008
• Est. Priority Date: 04/04/2005
• Status: Abandoned Application

• Current Assignee: United Technologies Corporation (Rtx Corporation)
• Original Assignee: United Technologies Corporation (Rtx Corporation)
• Inventors: Hanlon, Thomas R.
• Application Number:
  US11/944,848
• Publication Number:
  US 20080124542A1
• Time in Patent Office: Days
• US Class Current: 428/334
• CPC Class Codes: C23C 10/52 more than one element being diffused in one step
• CPC Class Codes: C23C 10/60 After-treatment
• CPC Class Codes: C23C 18/165 Multilayered product layered product B32B
• CPC Class Codes: C23C 18/1692 Heat-treatment
• CPC Class Codes: C23C 18/34 using reducing agents
• CPC Class Codes: C23C 26/00 Coating not provided for in groups C23C2/00 - C23C24/00
• CPC Class Codes: C23C 30/00 Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process C23C26/00, C23C28/00 take precedence
• CPC Class Codes: C25D 3/22 of zinc
• CPC Class Codes: C25D 5/34 Pretreatment of metallic surfaces to be electroplated
• CPC Class Codes: C25D 5/50 by heat-treatment
• CPC Class Codes: Y10T 428/12493 Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
• CPC Class Codes: Y10T 428/12576 Boride, carbide or nitride component
• CPC Class Codes: Y10T 428/12771 Transition metal-base component
• CPC Class Codes: Y10T 428/263 Coating layer not in excess of 5 mils thick or equivalent
• CPC Class Codes: Y10T 428/31678 Of metal

Abstract

A Ni-based first material is deposited on a substrate by electroless plating. A Zn-based second material is deposited on the first material. One or more components of at least one of the first and second materials are diffused into the other. The diffusion creates a ZnNi alloy layer enhancing corrosion resistance.

Claims

1. A method for coating comprising:

applying a Ni-based first material atop a substrate by electroless NiB plating;

applying a Zn-based second material atop the first material; and

diffusing one or more components of at least one of the first and second materials into the other.

2. The method of claim 1 wherein:

the first material is applied directly atop the substrate; and

the second material is applied directly atop the first material.

3. The method of claim 1 wherein:

essentially no additional materials are applied.

4. The method of claim 1 further comprising:

applying a Cr-based third material after at least a major portion of the diffusing.

5. The method of claim 1 further comprising:

applying a Cr-based third material before at least a major portion of the diffusing.

6. The method of claim 1 wherein:

the diffusing comprises heating to a temperature of at least 300°

C. for a duration of at least one half hour.

7. The method of claim 1 wherein:

the diffusing comprises heating to a temperature of 300-500°

C. for a duration of 0.5-3 hours.

8. The method of claim 1 wherein:

the diffusing is effective to provide a degree of diffusion at least as high as a degree of diffusion obtained by heating to a temperature of 450°

C. for a duration of 1.5 hours.

9. The method of claim 1 wherein:

the diffusing is effective to provide a degree of diffusion at least as high as a degree of diffusion obtained by heating to a temperature of 300°

C. for a duration of 2.0 hours.

10. The method of claim 1 wherein:

the substrate is Ti-based.

11. The method of claim 1 wherein:

the applying of the first material comprises applying to a first thickness of 50-500 μ

m at a first location; and

the applying of the second material comprises applying to a second thickness of 5-20 μ

m at said first location.

12. The method of claim 1 wherein:

the applying of the first material comprises applying to an essentially uniform first thickness; and

the applying of the second material comprises applying to an essentially uniform second thickness less than the first thickness.

13. The method of claim 1 wherein:

the first material, as applied, comprises 1-10% B.

14. The method of claim 1 wherein:

the first material, as applied, comprises 2-6% B.

15. The method of claim 1 wherein:

the diffusing forms a region of essentially 10-25% Ni throughout a depth of at least 50% of said second thickness.

16. A coated substrate formed by the method of claim 1.

17. A method for coating comprising:

applying by electroless NiB plating a Ni-based first material atop a substrate;

applying a Zn-based second material atop the first material; and

a step for forming a NiZn alloy from the first and second materials.

18. The method of claim 17 wherein:

the applying of the first material consists essentially of said electroless plating; and

the step for forming comprises heating to a temperature of at least 400°

C. for a duration of at least 1 hour

19. A coated article comprising:

a substrate; and

a coating system having a compositional gradient having;

a first region having;

a Ni content of at least 50%;

a B content of at least 1%; and

a thickness of at least 10 μ

m; and

a second region outboard of the first region and having;

a Zn content of at least 50%;

a Ni content of at least 10%; and

a thickness of at least 4 μ

m.

20. The article of claim 19 wherein:

the substrate is Ti-based.

21. The article of claim 19 wherein:

the first region Ni content is at least 80%;

the first region B content is at least 5%;

the second region Zn content is at least 70%;

the second region has a B content less than one fifth of the first region B content; and

the coating system has a transition region between the first and second regions having a thickness of no more than 10 μ

m.