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US4486285A
Expired / Lapsed
US
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Chromium coating with high hardness capable of resisting wear, strain surface fatigue and corrosion all at the same time
Assignee: Centre Stephanois de Recherches Mecaniques Hydromecanique et Frottement SA
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Filing: 1982-09-02
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Granted: 1984-12-04
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Expires: 2002-09-02
Abstract
Abstract By cathode sputtering in a reactive environment, a coating of a solid solution of chromium and an element such as nitrogen, carbon, phosphorus, boron or silicon is deposited. The content of the above element is higher than the saturation limit of the solid solution in chromium. It ranges between Tm=0.2% and TM=3% by weight for carbon and between Tm=0.04% and TM=3.5% by weight for nitrogen.
Inventors
- 👤 Andre Aubert
- 👤 Jacques Chevallier
- 👤 Antoine Gaucher
- 👤 Jean-Paul Terrat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 03:11
CPC Classifications
C; C23; C23C; C23C14/00; C23C14/06; C23C14/14; C23C14/0021; C23C14/0036
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
156 words
A method of chromium plating a workpiece in the presence of a preselected element capable of forming a solid solution with chromium, said preselected element being selected from a group consisting of carbon and nitrogen, said method comprising the steps of: placing said workpiece in a vacuum; cathode sputtering said chromium onto a surface of said workpiece; and introducing said preselected element during said cathode sputtering in a predetermined proportion to said chromium, said predetermined proportion being between a lower limit T m and a higher limit T M such that between these two limits none of the compounds and phases thermodynamically predictable from the equilibrium diagram of chromium with said preselected element are found in the coating, the lower limit T m being the saturation limit of the equilibrium diagram of said preselected element in chromium, said predetermined proportion thereby being outside of the thermodynamic equilibrium range of solution of said preselected element in chromium.
Claim 2
Independent Claim
156 words
A method of chromium plating a workpiece in the presence of a preselected element capable of forming a solid solution with chromium, said preselected element being selected from a group consisting of carbon and nitrogen, said method comprising the steps of: placing said workpiece in a vacuum; cathode sputtering said chromium onto a surface of said workpiece; and introducing said preselected element during said cathode sputtering in a predetermined proportion to said chromium, said predetermined proportion being between a lower limit T m and a higher limit T M such that between these two limits none of the compounds and phases thermodynamically predictable from the equilibrium diagram of chromium with said preselected element are found in the coating, the lower limit T m being the saturation limit of the equilibrium diagram of said preselected element in chromium, said predetermined proportion thereby being outside of the thermodynamic equilibrium range of solution of said preselected element in chromium.
Claim 3
Dependent Claim
30 words
The method of chromium plating of claim 1 wherein said preselected element is introduced in a reactive environment capable of forming at least one solid solution of insertion with chromium.
Claim 4
Dependent Claim
15 words
The method of chromium plating of claim 2 wherein said reactive environment comprises hydrocarbon gas.
Claim 5
Dependent Claim
14 words
The method of chromium plating of claim 3 wherein said hydrocarbon gas is methane.
Claim 6
Dependent Claim
27 words
The method of chromium plating of claim 1 wherein said preselected element is introduced in a non-reactive environment, said preselected element being introduced directly into said workpiece.
Claim 7
Dependent Claim
20 words
The method of chromium plating of claim 5 wherein said preselected element is introduced into said workpiece in elemental form.
Claim 8
Dependent Claim
27 words
The method of chromium plating of claim 5 wherein said preselected element is introduced into said workpiece in the form of a compound containing said preselected element.
Claim 9
Dependent Claim
13 words
The method of chromium plating of claim 7 wherein said compound is hydrocarbon.
Claim 10
Dependent Claim
36 words
The method of chromium plating of claim 1 wherein said preselected element is carbon and further wherein said lower limit T m is 0.2% by weight and the higher limit T M is 0.3% by weight.
Claim 11
Dependent Claim
36 words
The method of chromium plating of claim 1 wherein said preselected element is nitrogen and further wherein said lower limit T m is 0.04% by weight and the higher limit T M is 3.5% by weight.
Claim 12
Dependent Claim
10 words
The plated workpiece formed by the method of claim 1.
Claim 13
Dependent Claim
10 words
The plated workpiece formed by the method of claim 5.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-12-04 | 1988-06-04 | 1988-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-04 | 1992-06-04 | 1992-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-04 | 1996-06-04 | 1996-12-04 | $7700.00 | Window Closed / Lapsed |