Redox couple-based mitigation of fluid-flow-driven electrochemical surface degradation

Patent metadata

Field	Value
Publication number	US-9650586-B2
Application number	US-201313948413-A
Country	US
Kind code	B2
Filing date	Jul 23, 2013
Priority date	Jul 23, 2013
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

The present disclosure relates to methods, systems, hydraulic fluids and additives for reducing the rate of surface current degradation for components in a hydraulic system, wherein the hydraulic system is exposed to phosphate-ester-based hydraulic fluid.

First claim

What is claimed is:

1. A method
for reducing rate of surface current induced degradation for components in hydraulic system components, the hydraulic system having components exposed to phosphate-ester-based hydraulic fluid, the method comprising the step of:
adding a redox couple to the hydraulic fluid;
wherein the hydraulic fluid comprising the redox couple is in contact with the hydraulic system.

2. The method of claim 1 , wherein said redox couple provides a path for both oxidation currents and reduction currents in the hydraulic system.

3. The method of claim 1 , wherein the redox couple comprises a metallocene couple.

4. The method of claim 1 , wherein the redox couple comprises a sandwich compound of the formula: M(A r ) 2 +/0 , where M is a transition metal, and A r is an aryl compound.

5. The method of claim 1 , wherein the redox couple comprises a metallocene couple having the formula: M(C p ) 2 +/0 , where M is a transition metal, and C p is a cyclopentadiene-containing compound.

6. The method of claim 4 , wherein the transition metal is selected from the group consisting of: Fe, Co, Mn, Cr, Ni, and V.

7. The method of claim 5 , wherein the transition metal is selected from the group consisting of: Fe, Co, Mn, Cr, Ni, and V.

8. The method of claim 1 , wherein the redox couples are selected from the group consisting of: Fe(cyclopentadiene) 2 + and Fe(cyclopentadiene) 2 0 ;
Fe(pentamethylcyclopentadiene) 2 + and Fe(pentamethylcyclopentadiene) 2 0 ;
Ni(cyclopentadiene) 2 + and Ni(cyclopentadiene) 2 0 ; Co(cyclopentadiene) 2 + and
Co(cyclopentadiene) 2 0 ; decamethylferricinum + and decamethylferrocene 0 ; and
Fe(pentamethylcyclopentadiene) 2 + and
Fe(pentamethylcyclopentadiene) 2 0 .

9. An hydraulic system comprising:
a phosphate-ester-based hydraulic fluid, and
a redox couple.

10. The system of claim 9 , wherein said redox couple provides a path for both oxidation current and reduction currents in the hydraulic system.

11. The system of claim 9 , wherein the redox couple comprises a metallocene couple.

12. The system of claim 9 , wherein the redox couple comprises a sandwich compound having the formula: M(A r ) 2 +/0 , where M is a transition metal, and A r is an aryl compound.

13. The system of claim 9 , wherein the redox couple comprises a metallocene couple having the formula: M(C p ) 2 +/0 , where M is a transition metal, and C p is acyclopentadiene-containing compound.

14. The system of claim 9 , wherein the redox couple is selected from the group consisting of: Fe(cyclopentadiene) 2 + and Fe(cyclopentadiene) 2 0 ;
Fe(pentamethylcyclopentadiene) 2 + and Fe(pentamethylcyclopentadiene) 2 0 ;
Ni(cyclopentadiene) 2 + and Ni(cyclopentadiene) 2 0 ; Co(cyclopentadiene) 2 + and
Co(cyclopentadiene) 2 0 ; decamethylferricinum + and decamethylferrocene 0 ; and
Fe(pentamethylcyclopentadiene) 2 + and
Fe(pentamethylcyclopentadiene) 2 0 .

15. An hydraulic fluid for use in a hydraulic system, the fluid comprising:
a phosphate-ester-based compound, and
a redox couple, said redox couple comprising a metallocene couple.

16. The fluid of claim 15 , wherein the redox couple provides a path for both oxidation currents and reduction currents in the hydraulic fluid.

17. The fluid of claim 15 , wherein the redox couple comprises a sandwich compound having the formula: M(A r ) 2 +/0 , where M is a transition metal, and A r is an aryl compound.

18. The fluid of claim 15 , wherein the redox couple comprises a metallocene couple having the formula: M(C p ) 2 +/0 , where M is a transition metal, and C p is a cyclopentadiene-containing compound.

19. The fluid of claim 17 , wherein the transition metal is selected from the group consisting of: Fe, Co, Mn, Cr, Ni, and V.

20. The fluid of claim 18 , wherein the transition metal is selected from the group consisting of: Fe, Co, Mn, Cr, Ni, and V.

21. The fluid of claim 15 , wherein the redox couple is selected from the group consisting of: Fe(cyclopentadiene) 2 + and Fe(cyclopentadiene) 2 0 ;
Fe(pentamethylcyclopentadiene) 2 + and Fe(pentamethylcyclopentadiene) 2 0 ;
Ni(cyclopentadiene) 2 + and Ni(cyclopentadiene) 2 0 ; Co(cyclopentadiene) 2 + and
Co(cyclopentadiene) 2 0 ; decamethylferricinum + and decamethylferrocene 0 ;
Fe(pentamethylcyclopentadiene) 2 + and Fe(pentamethylcyclopentadiene) 2 0 .

22. An object comprising the hydraulic system of claim 9 .

23. The object of claim 22 , wherein said object is selected from the group consisting of: an aircraft, a vehicle, and a stationary object.

Assignees

• Boeing Co

Inventors

• Hager Harold E

Classifications

• C10N2040/13

  Aircraft turbines · CPC title

• C10N2030/12

  Inhibition of corrosion, e.g. anti-rust agents or anti-corrosives · CPC title

• C10N2040/08

  Hydraulic fluids, e.g. brake-fluids · CPC title

• C10M169/04 Primary

  Mixtures of base-materials and additives · CPC title

• C09K15/32 Primary

  containing {two or more of} boron, silicon, phosphorus, selenium, tellurium or a metal · CPC title