Ottis J Horne

US Patent:

42846129, Aug 18, 1981

Filed:

Jan 28, 1980

Appl. No.:

6/115683

Inventors:

Ottis J. Horne - Johnson City TN
Lloyd I. Grindstaff - Elizabethton TN

Assignee:

Great Lakes Carbon Corporation - New York NY

International Classification:

C01B 3136

US Classification:

423345

Abstract:

Organic fibers are oxidized, ground and blended with a source of silica. Heat treatment of the blend in the range of 1400. degree. to 1700. degree. C. results in the formation of SiC whiskers. Various fibers including PAN, pitch and rayon which can be processed to form carbon and/or graphite fibers can be used as the carbon source. Ashed rice hulls as the source of silica are blended with the chopped fiber to form the SiC whiskers.

US Patent:

42833752, Aug 11, 1981

Filed:

Jan 28, 1980

Appl. No.:

6/115684

Inventors:

Ottis J. Horne - Johnson City TN
David E. Ramsey - Johnson City TN

Assignee:

Great Lakes Carbon Corporation - New York NY

International Classification:

C01B 3136

US Classification:

423345

Abstract:

Silicon carbide whiskers useful for reinforcement of metals are manufactured from SiO. sub. 2 and carbon. Rice hulls are ashed in air at approximately 620. degree. C. to obtain amorphous SiO. sub. 2, which is then blended with fine particle size carbon. The mixture is rapidly heated under CO atmosphere to 1500. degree. C. , and when the temperature reaches that point the CO atmosphere is flushed with argon, the SiC whiskers forming in the argon atmosphere. The product is purified by ashing in air to remove excess carbon and/or washed with HF to remove unreacted SiO. sub. 2.