FreshPatents.com Logo
stats FreshPatents Stats
12 views for this patent on FreshPatents.com
2014: 1 views
2012: 1 views
2011: 5 views
2010: 5 views
Updated: July 25 2014
newTOP 200 Companies filing patents this week


    Free Services  

  • MONITOR KEYWORDS
  • Enter keywords & we'll notify you when a new patent matches your request (weekly update).

  • ORGANIZER
  • Save & organize patents so you can view them later.

  • RSS rss
  • Create custom RSS feeds. Track keywords without receiving email.

  • ARCHIVE
  • View the last few months of your Keyword emails.

  • COMPANY DIRECTORY
  • Patents sorted by company.

Follow us on Twitter
twitter icon@FreshPatents

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

last patentdownload pdfimage previewnext patent


Title: Reactive sintering to eliminate metal inserts in carbon-carbon brake discs.
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. ...


USPTO Applicaton #: #20100044170 - Class: 188218XL (USPTO) - 02/25/10 - Class 188 


view organizer monitor keywords


The Patent Description & Claims data below is from USPTO Patent Application 20100044170, Reactive sintering to eliminate metal inserts in carbon-carbon brake discs.

last patentpdficondownload pdfimage previewnext patent

US 20100044170 A1 20100225 US 12196511 20080822 12 20060101 A
F
16 D 65 12 F I 20100225 US B H
20060101 A
B
22 F 7 04 L I 20100225 US B H
US 188218XL 419 9 REACTIVE SINTERING TO ELIMINATE METAL INSERTS IN CARBON-CARBON BRAKE DISCS Simpson Allen H.
Buchanan MI US
omitted US
La Forest Mark L.
Granger IN US
omitted US
Vanderheyden Gregory
South Ben IN US
omitted US
Mukasyan Alexander
Granger IN US
omitted US
HONEYWELL INTERNATIONAL INC.
Law Department AB 2, P.O. Box 2245 Morristown NJ 07962-9806 US

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.

FIELD OF THE INVENTION

This invention relates to carbon-carbon composite brake discs, and more particularly, to brake disc drive insert slots in carbon-carbon composite brake discs. The present invention provides an improved surface within the brake disc drive insert slots.

BACKGROUND OF THE INVENTION

Carbon-carbon composite brake discs used in the aerospace industry typically have metal inserts attached to them. Specifically, the metal inserts are attached to slots in the interior faces of the brake discs (rotors or stators). Those slots function to facilitate the transmission of torque to the brake discs. The metal inserts for stators serve to provide a surface that will transmit torque from the torque tube of the axle to the brake disc without crushing the face of the carbon-carbon composite material. Rotor inserts are used as the media to transmit torque form the wheel drive key interface to the brake discs. The metal inserts—typically held in place by rivets, adhesive, etc.—serve this purpose. However, they are relatively expensive additions to the brake discs. Labor is expended drilling holes for and attaching the inserts. Damage sometimes occurs to the carbon-carbon brake disc during installation or removal of rivets. Also, the inserts add significant weight to the brake assembly.

U.S. Pat. No. 5,273,140 describes a brake disc annular drive insert which comprises a generally cylindrical member with radially extending flanges at opposite axial ends thereof. The drive insert includes a generally cylindrical body having an opening at one side thereof which extends diametrically into the body and terminates at a point between the center of revolution of the body and an outer surface of the body. The opening in the body extends to an inner surface of the body to provide a generally rectangular opening for receiving a spline of a torque tube. The drive insert is typically made of steel. The flanges of the drive insert may comprise either generally annular flanges shaped complementary with the generally cylindrical body and or may be truncated at a side opposite the opening in the body.

US 2007/0175709 describes brake disc drive inserts for use in carbon-carbon composite brake discs. A rotatable brake disc annular drive insert includes a cylindrical steel body having one side of the body truncated to provide an insert opening which extends axially through the body. The insert opening extends into the body along a diameter of the body and the insert opening terminates at a radially extending surface located between the revolutional center of the body and an outer surface of the body. End flanges extend radially outwardly from the outer surface of the body to provide for axial positioning of the drive insert relative to a brake disc. The insert opening has a lining comprising carbon-carbon composite material. This low friction carbon-carbon composite material bed that is positioned between the steel insert component and the torque tube spline location provides significantly lower friction and enables significantly greater disc clamping and brake torque.

Other prior art of interest includes: US 2007/0235126 A1, entitled BONDING OF CARBON-CARBON COMPOSITES USING TITANIUM CARBIDE; US 2007/0235123 A1, entitled APPARATUS AND METHODS FOR BONDING CARBON-CARBON COMPOSITES THROUGH A REACTANT LAYER; copending application Ser. No. 11/730,373, entitled BONDING OF CARBON FIBERS TO METAL INSERTS FOR USE IN COMPOSITES; and US 2007/0193836 A1, entitled METHOD AND BRAKE DISC WITH COMPOSITE INSERT MEMBER.

SUMMARY OF THE INVENTION

The present invention eliminates the need for inserts, and the drilling of rivet holes. Instead, the present invention toughens the face of the carbon-carbon composite material so that it will not crush under pressure.

In accordance with this invention, a brake disc rotor or stator is manufactured by conventional methods through the final machining process which provides slots in the interior face of the brake disc. At that point, this invention applies a paste to the areas where force is applied to the rotor slot faces or to the stator slot faces. The paste is comprised of a fine powder of a carbide-forming metal along with fine carbon powder. The metal and carbon powders are suspended in an organic binder. 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. The ceramic created in this way “cools” very quickly to the temperature of the carbon-carbon composite. The brake disc is then cooled to ambient temperature. The resulting brake disc has a tough, hard, abrasion-resistant ceramic surface on the portion of the brake disc slot that bears pressure. At this point, the discs are processed through additional standard processes, such as application of antioxidant.

BRIEF DESCRIPTION OF THE DRAWINGS

The following drawings are illustrative only, and non-limiting. They illustrate possible ways in which the present invention, which toughens the face of the carbon-carbon compose material, may be implemented. However, persons skilled in the art will readily envision other ways in which the benefits of the present invention may be obtained.

FIG. 1A is a top plan view of a known type of aircraft carbon-carbon composite brake disc stator coupled with a torque tube via annular drive inserts.

FIG. 1B is an enlarged view corresponding to the circled section of FIG. 1A, but modified in accordance with the present invention.

FIG. 2A is an isometric view of a known type of aircraft carbon-carbon composite brake disc rotor.

FIG. 2B is an enlarged view corresponding to the circled section of FIG. 2A, but modified in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

This invention provides a method of manufacturing a brake disc rotor or brake disc stator, wherein the rotor or stator has a tough, hard, abrasion-resistant ceramic surface on the portion of the brake disc slot that bears pressure. The method of the invention includes the following four steps.

Step (1) contemplates providing a carbon-carbon composite brake disc rotor or stator having slot slots in the interior face of said brake disc. These brake disc rotors or stators are manufactured by conventional methods through the final machining process which provides slots in the interior faces of the brake discs.

Step (2) contemplates applying a paste, comprised of a fine powder of titanium, zirconium, hafnium, and/or vanadium along with fine carbon powder suspended in an organic binder, to the areas where force will be applied to the rotor or stator slot faces. In a preferred embodiment, the fine powder is titanium powder having an average particle diameter ranging from 25 to 250 microns. In a more preferred embodiment, the average particle diameter of the titanium powder is about 45 microns. In a preferred embodiment, the carbon powder is powdered graphite and the average diameter of the graphite particles ranges from 1 to 10 microns. In a more preferred embodiment, the average particle diameter of the graphite particles is about 2 microns. In a preferred embodiment, the mole ratio of metal powder to carbon powder ranges from 3:1 to 0.5:1. In a preferred embodiment, the organic binder is a phenolic binder, an epoxy binder, or an alginate binder. In a preferred embodiment, the paste is applied to the areas where force will be applied to the rotor or stator slot faces in a thickness ranging from 30 microns to ¼ inch. In an especially preferred embodiment, the paste is a layer of titanium powder and carbon powder about 1/16 inch in thickness.

Step (3) contemplates placing the disc into a furnace having a nitrogen-containing atmosphere, and heating the disc to the ignition temperature. In a preferred embodiment, the furnace is provided with an atmosphere containing nitrogen—for instance, air or pure nitrogen gas—at a pressure ranging from 0.2 to 20 atmospheres. In a preferred embodiment, this heating step is conducted at a temperature of from 400-600° C.

Step (4) contemplates cooling the brake disc to ambient temperature. When the furnace in step (3) reaches the ignition temperature, a combustion reaction begins that creates a molten liquid ceramic material on the slot faces in the brake discs. The ceramic created in this way “cools” very quickly to the temperature of the carbon-carbon composite. This initial rapid cooling is followed by cooling the brake disc to ambient temperature, generally by the application of cooling means such as refrigerants and/or blowing air.

This invention also provides a slotted brake disc rotor or slotted brake disc stator which has a tough, hard, abrasion-resistant ceramic surface on the portion of the brake disc slot that bears pressure, said rotor or stator being manufactured by a method of described above.

Examples of the metals which may be used in this invention are titanium, zirconium, hafnium, and/or vanadium. Titanium carbide provides a ceramic with an especially high specific heat. These metal powders typically ignite at around 450° C. in a nitrogen atmosphere. Reaction between nitrogen and metal provides the low ignition temperature.

Examples of binders which may be used in this invention include phenolic binders, epoxy binders, and alginates. However, any organic binder which can provide a paste of the metal powder being used can be employed.

With reference to FIG. 1A, an aircraft carbon-carbon composite brake disc stator 10 is generally annular in shape and includes a central generally annular opening 14. A plurality of slot openings or recesses receiving therein brake disc annular drive inserts 20 is located about the periphery of opening 14. Recesses 16 of disc 10 are generally annularly shaped slots extending radially outwardly from opening 14 of disc 10. Annular drive inserts 20 couple torque tube 6 with disc 10. The torque tube is non-rotatably coupled with an axle (not shown) of an aircraft.

As illustrated in FIG. 1B, torque tube 6 includes radially extending short spines 8 which extend within the respective annular drive slots or openings 21. In accordance with the present invention, each opening 21 (slot) is lined with an area of toughened carbon-carbon composite material 19.

FIG. 2A shows an aircraft carbon-carbon composite brake disc stator that is generally annular in shape and that includes a central generally annular opening. A plurality of slot openings or recesses is located about the outer periphery of the rotor.

As illustrated in FIG. 2B, in accordance with the present invention, each opening 21 (slot) is lined with an area of toughened carbon-carbon composite material 19.

EXAMPLES Example 1

A paste is prepared from 1.0 mol of titanium powder and 0.8 mol of carbon powder in a liquid phenolic binder. This paste is applied in a layer approximately ⅛ inch thick to the faces of slot slots in a carbon-carbon composite brake disc stator. The composite disc having the paste-lined slot slots is placed in a furnace which has a pure nitrogen atmosphere at 1 atmosphere of pressure. Ignition occurs at about 410° C. The maximum combustion temperature reached is 2340° C. The resulting ceramic layer on the faces of the slot slots comprises 0.9 mol TiC and 0.1 mol TiN. This ceramic layer is a refractory material which is stable up to about 3000° C. and which has a Rockwell Hardness, A scale, of about 80 HRA.

Example 2

A paste is prepared from 1.0 mol of zirconium powder and 1.0 mol of carbon powder in a liquid epoxy binder. This paste is applied in a layer approximately 3/16 inch thick to the faces of slot slots in a carbon-carbon composite brake disc rotor. The composite disc having the paste-lined slot slots is placed in a furnace which has an air (nitrogen, oxygen, etc.) atmosphere at 0.5 atmospheres of pressure. Ignition occurs at about 600° C. The maximum combustion temperature reached is 2500° C. The resulting ceramic layer on the faces of the slot slots comprises 1.0 mol ZrC and 0.2 mol ZrN. This ceramic layer is a refractory material which is stable up to about 3200° C. and which has a Rockwell Hardness, A scale, of about 95 HRA.

Example 3

A paste is prepared from 1.0 mol of vanadium powder and 0.5 mol of carbon powder in a liquid alginate binder. This paste is applied in a layer approximately 1/16 inch thick to the faces of slot slots in a carbon-carbon composite brake disc stator. The composite disc having the paste-lined slot slots is placed in a furnace which contains pressurized nitrogen gas. Ignition occurs at about 410° C. The maximum combustion temperature reached is 2400° C. The resulting ceramic layer on the faces of the slot slots comprises 1.0 mol VC and 0.25 mol VN. This ceramic layer is a refractory material which is stable up to about 3000° C. and which has a Rockwell Hardness, A scale, of about 90 HRA.

While the present invention has been described with respect to detailed examples of its implementation, the invention is capable of numerous modifications, rearrangements, and alterations, and such are intended to be within the spirit and scope of the foregoing disclosure and the appended claims.

What is claimed is: 1. A method of manufacturing a slotted brake disc rotor or stator that has a tough, hard, abrasion-resistant ceramic surface on the portion of the brake disc slot that bears pressure, which method comprises: i.) providing a carbon-carbon composite brake disc rotor or stator having slot slots in the interior face of said brake disc; ii.) applying a paste, comprised of a fine powder of titanium, zirconium, hafnium, and/or vanadium along with fine carbon powder suspended in an organic binder, to the areas where force will be applied to the rotor or stator slot faces; iii.) placing the disc into a furnace having a nitrogen-containing atmosphere, and heating the disc to the ignition temperature; and iv.) cooling the brake disc to ambient temperature. 2. The method of claim 1, wherein the metal powder is titanium powder. 3. The method of claim 1, wherein the average diameter of the titanium powder particles ranges from 25 to 250 microns. 4. The method of claim 3, wherein the average diameter of the titanium powder particles is about 45 microns. 5. The method of claim 1, wherein the carbon powder is powdered graphite and the average diameter of the graphite particles ranges from 1 to 10 microns. 6. The method of claim 5, wherein the average diameter of the graphite particles is about 2 microns. 7. The method of claim 1, wherein the mole ratio of metal powder to carbon powder ranges from 3:1 to 0.5:1. 8. The method of claim 1, wherein the binder is a phenolic binder, an epoxy binder, or an alginate binder. 9. The method of claim 1, wherein the paste is applied in a thickness ranging from 30 microns to ¼ inch. 10. The method of claim 9, wherein the paste is a layer of titanium powder and carbon powder about 1/16 inch in thickness. 11. The method of claim 1, wherein the furnace in step iii.) is provided with an atmosphere containing nitrogen at a pressure ranging from 0.2 to 20 atmospheres. 12. The method of claim 11, wherein said nitrogen-containing atmosphere is air. 13. The method of claim 11, wherein said nitrogen-containing atmosphere is pure nitrogen gas. 14. The method of claim 11, wherein heating step iii.) is conducted at a temperature of from 400-600° C. 15. A brake disc rotor or stator that has a tough, hard, abrasion-resistant ceramic surface on the portion of the brake disc slot that bears pressure, manufactured by the method of claim 1.


Download full PDF for full patent description/claims.

Advertise on FreshPatents.com - Rates & Info


You can also Monitor Keywords and Search for tracking patents relating to this Reactive sintering to eliminate metal inserts in carbon-carbon brake discs patent application.
###
monitor keywords



Keyword Monitor How KEYWORD MONITOR works... a FREE service from FreshPatents
1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored.
3. Each week you receive an email with patent applications related to your keywords.  
Start now! - Receive info on patent apps like Reactive sintering to eliminate metal inserts in carbon-carbon brake discs or other areas of interest.
###


Previous Patent Application:
Brake disc having corrugated outer periphery
Next Patent Application:
Damping force variable valve of shock absorber
Industry Class:
Brakes
Thank you for viewing the Reactive sintering to eliminate metal inserts in carbon-carbon brake discs patent info.
- - - Apple patents, Boeing patents, Google patents, IBM patents, Jabil patents, Coca Cola patents, Motorola patents

Results in 0.43615 seconds


Other interesting Freshpatents.com categories:
Qualcomm , Schering-Plough , Schlumberger , Texas Instruments ,

###

Data source: patent applications published in the public domain by the United States Patent and Trademark Office (USPTO). Information published here is for research/educational purposes only. FreshPatents is not affiliated with the USPTO, assignee companies, inventors, law firms or other assignees. Patent applications, documents and images may contain trademarks of the respective companies/authors. FreshPatents is not responsible for the accuracy, validity or otherwise contents of these public document patent application filings. When possible a complete PDF is provided, however, in some cases the presented document/images is an abstract or sampling of the full patent application for display purposes. FreshPatents.com Terms/Support
-g2-0.2324
     SHARE
  
           

FreshNews promo


stats Patent Info
Application #
US 20100044170 A1
Publish Date
02/25/2010
Document #
12196511
File Date
08/22/2008
USPTO Class
188218XL
Other USPTO Classes
419/9
International Class
/
Drawings
2



Follow us on Twitter
twitter icon@FreshPatents