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

Patent metadata

Field	Value
Publication number	US-9546338-B2
Application number	US-201615010073-A
Country	US
Kind code	B2
Filing date	Jan 29, 2016
Priority date	Jul 23, 2013
Publication date	Jan 17, 2017
Grant date	Jan 17, 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 hydraulic fluid for use in a hydraulic fluid system, said hydraulic fluid comprising:
a phosphate-ester-based compound; and
an additive;
wherein said additive comprises a redox couple, said redox couple comprising a metallocene couple.

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

3. The hydraulic fluid of claim 1 , 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.

4. The hydraulic fluid 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.

5. The hydraulic fluid of claim 1 , 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 ;
decamethylferricinue and decamethylferrocene 0 ; and
Fe(pentamethylcyclopentadiene) 2 + and
Fe(pentamethylcyclopentadiene) 2 0 .

6. An object comprising the hydraulic fluid of claim 1 .

7. A method for reducing rate of surface current induced degradation for components in a hydraulic system, the method comprising the step of:
adding a hydraulic fluid to the hydraulic system, said hydraulic fluid comprising an additive, said additive comprising:
a redox couple.

8. The method of claim 7 , wherein said redox couple provides a path for both oxidation currents and reduction currents in the hydraulic system.

9. The method of claim 7 , wherein the redox couple comprises a metallocene couple.

10. The method of claim 7 , 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.

11. The method of claim 7 , 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.

12. The method of claim 7 , 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 .

Assignees

• Boeing Co

Inventors

• Hager Harold E

Classifications

• C10N2040/08

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

• C10N2030/12

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

• C10N2040/13

  Aircraft turbines · CPC title

• C10M169/04 Primary

  Mixtures of base-materials and additives · CPC title

• F15B21/04 Primary

  Special measures taken in connection with the properties of the fluid · CPC title