Reactive sintering to eliminate metal inserts in carbon-carbon brake discs

Patent metadata

Field	Value
Publication number	US-10100889-B2
Application number	US-201313891994-A
Country	US
Kind code	B2
Filing date	May 10, 2013
Priority date	Aug 22, 2008
Publication date	Oct 16, 2018
Grant date	Oct 16, 2018

Abstract

A brake disc rotor or stator is manufactured with slots in the interior face of the disc. A paste comprised of a fine powder of a carbide-forming metal along with fine carbon powder, suspended in an organic binder, is applied to the force-bearing areas in the rotor slot faces or the stator slot faces. The disc is then placed into a furnace in a nitrogen atmosphere and heated to the ignition temperature. When the furnace reaches the ignition temperature, a combustion reaction begins that creates a molten liquid ceramic material on the slot face. Upon cooling, the resulting brake disc has a tough, hard, abrasion-resistant ceramic surface on the portion of the brake disc slot that bears pressure.

First claim

What is claimed is:

1. A method comprising:
forming a ceramic layer on a slot face of a brake disc rotor or stator, wherein the brake disc rotor or stator comprises a surface including a slot, wherein the slot defines the slot face, and wherein forming the ceramic layer on the slot face comprises:
applying a paste to the slot face of the brake disc rotor or stator, wherein the paste comprises a fine powder suspended in an organic binder;
heating the brake disc rotor or stator at least to an ignition temperature of the paste in an atmosphere comprising nitrogen to initiate a combustion reaction that forms the ceramic layer on the slot face of the brake disc rotor or stator; and
cooling the brake disc rotor or stator to ambient temperature, wherein, upon cooling, the ceramic layer resists abrasion, wherein the fine powder comprises metal powder and carbon powder, and wherein a molar ratio of the metal powder to the carbon powder is between 3:1 and 0.5:1.

2. The method of claim 1 , wherein the organic binder comprises a phenolic binder, an epoxy binder, or an alginate binder.

3. The method of claim 1 , wherein applying the paste to the slot face of the brake disc rotor or stator comprises applying the paste to the slot face in a thickness between 30 microns and 0.25 inches.

4. The method of claim 1 , wherein the fine powder comprises titanium powder.

5. The method of claim 4 , wherein an average particle diameter of the titanium powder is between 25 microns and 250 microns.

6. The method of claim 4 , wherein an average particle diameter of the titanium powder is about 45 microns.

7. The method of claim 1 , wherein the fine powder comprises powdered graphite and wherein an average particle diameter of the powdered graphite is between 1 micron and 10 microns.

8. The method of claim 7 , wherein the average particle diameter of the powdered graphite is about 2 microns.

9. The method of claim 1 , wherein the atmosphere comprising nitrogen is air.

10. The method of claim 1 , wherein the atmosphere is pure nitrogen gas.

11. The method of claim 1 , wherein heating the brake disc rotor or stator at least to the ignition temperature comprises heating the brake disc rotor or stator at a temperature between 400 degrees Celsius and 600 degrees Celsius.

12. The method of claim 1 , wherein the fine powder comprises at least one of titanium, zirconium, hafnium, or vanadium.

13. The method of claim 1 , wherein forming the ceramic layer on the slot face of the brake disc rotor or stator comprises forming the ceramic layer directly on the slot face of the brake disc rotor or stator.

14. The method of claim 1 , wherein heating the brake disc rotor or stator at least to the ignition temperature of the paste comprises placing the brake disc rotor or stator including the paste applied to the slot face into a furnace comprising the atmosphere comprising nitrogen.

15. The method of claim 1 , wherein one or more exterior surfaces of the brake disc rotor or stator define an inner circumference of the brake disc rotor or stator, an outer circumference of the brake disc rotor or stator, and a plurality of slots along at least one of the inner circumference or the outer circumference, wherein the one or more exterior surfaces comprise a plurality of slot faces, and each slot of the plurality of slots defines a slot face of the plurality of slot faces, the method further comprising forming the ceramic layer on each slot face of the plurality of slot faces.

16. The method of claim 1 , wherein the combustion reaction creates a molten liquid ceramic material on the slot face of the brake disc rotor or stator.

17. The method of claim 1 , wherein the slot is configured to receive a spline of a torque tube.

18. The method of claim 1 , wherein the metal powder comprises a carbide-forming metal powder.

19. A method comprising:
forming a ceramic layer on a slot face of a brake disc rotor or stator, wherein the brake disc rotor or stator comprises a surface including a slot, wherein the slot defines the slot face, and wherein forming the ceramic layer on the slot face comprises:
applying a paste to the slot face of the brake disc rotor or stator, wherein the paste comprises a fine powder suspended in an organic binder;
heating the brake disc rotor or stator at least to an ignition temperature of the paste in an atmosphere comprising nitrogen to initiate a combustion reaction that forms the ceramic layer on the slot face of the brake disc rotor or stator; and
cooling the brake disc rotor or stator to ambient temperature, wherein, upon cooling, the ceramic layer resists abrasion, wherein the atmosphere contains nitrogen at a pressure between 0.2 and 20 atmospheres.

Assignees

• Honeywell Int Inc
• The Univ Of Notre Dame Du Lac

Inventors

• Simpson Allen H
• La Forest Mark L
• Vanderheyden Gregory
• Mukasyan Alexander

Classifications

• F16D69/025

  Compositions based on an organic binder · CPC title

• F16D2250/0053

  Hardening · CPC title

• F16D65/127 Primary

  characterised by properties of the disc surface; Discs lined with friction material · CPC title

• F16D65/125 Primary

  characterised by the material used for the disc body · CPC title

• F16D2200/0039

  Ceramics · CPC title