Low-temperature densification of carbon fiber preforms by colloidal graphite impregnation and mechanical consolidation

• US 5,993,905 A
• Filed: 10/29/1996
• Issued: 11/30/1999
• Est. Priority Date: 10/03/1995
• Status: Expired due to Fees

• Current Assignee: MSNW, Inc.
• Original Assignee: MSNW, Inc.
• Inventors: Sheehan, deceased, James E.
• Primary Examiner(s): Utech, Benjamin
• Assistant Examiner(s): UMEZ ERONINI, LYNETTE T
• Application Number:
  US08/786,392
• Time in Patent Office: 1,127 Days
• Field of Search: 427/294, 427/296, 427/375, 427/384
• US Class Current: 427/294
• CPC Class Codes: C04B 35/83 Carbon fibres in a carbon matrix
• CPC Class Codes: F16D 69/023 Composite materials containing carbon and carbon fibres or fibres made of carbonizable material

Abstract

An improved method for producing low-cost carbon--carbon composites based on impregnating carbon fiber mat preforms with liquid dispersions or suspensions of fine carbon particles and subsequent mechanical consolidation is disclosed. A highly porous preform of carbon fibers is impregnated by a liquid suspension of colloidal graphite and dried in air at low temperatures. Multiple impregnation and drying densification cycles provide a soft, flexible carbon--carbon composite. Subsequent mechanical consolidation methods, such as pressing or rolling, combined with rigidization by resin or pitch impregnation and carbonization, render a thin carbon--carbon composite of high bulk density. Prior to rigidization, the composite may be sewn with carbon yarns for property enhancement.

Claims

1. A method of fabricating a carbon--carbon composite which comprises

(a) impregnating a plurality of carbonaceous fiber preforms with a solution containing colloidal carbon;

(b) drying said plurality of impregnated carbonaceous fiber preforms;

(c) sewing together said plurality of impregnated carbonaceous fiber preforms; and

(d) mechanically consolidating said plurality of impregnated preforms.

2. A method of fabricating a carbon--carbon composite according to claim 1 wherein said impregnation of a carbonaceous fiber preform is accomplished by vacuum.

3. A method of fabricating a carbon--carbon composite according to claim 1 wherein said impregnation of a carbonaceous fiber preform is accomplished by drain impregnation.

4. A method of fabricating a carbon--carbon composite according to claim 1 wherein said drying is accomplished in air.

5. A method of fabricating a carbon--carbon composite according to claim 1 wherein said drying is accomplished in air at nonoxidizing temperatures.

6. A method of fabricating a carbon--carbon composite according to claim 1 wherein said mechanical consolidation is accomplished by pressing.

7. A method of fabricating a carbon--carbon composite according to claim 1 wherein said mechanical consolidation is accomplished by rolling.