David W Susnitzky

US Patent:

55255566, Jun 11, 1996

Filed:

Jun 7, 1995

Appl. No.:

8/484539

Inventors:

Stephen D. Dunmead - Midland MI
Alan W. Weimer - Midland MI
Daniel F. Carroll - Midland MI
Glenn A. Eisman - Midland MI
Gene A. Cochran - Midland MI
David W. Susnitzky - Midland MI
Donald R. Beaman - Midland MI
Kevin J. Nilsen - Midland MI

Assignee:

The Dow Chemical Company - Midland MI

International Classification:

C04B 35596
C04B 35577

US Classification:

501 92

Abstract:

Prepare silicon nitride-silicon carbide composite powders by carbothermal reduction of crystalline silica powder, carbon powder and, optionally, crystalline silicon nitride powder. The crystalline silicon carbide portion of the composite powders has a mean number diameter less than about 700 nanometers and contains nitrogen. The composite powders may be used to prepare sintered ceramic bodies and self-reinforced silicon nitride ceramic bodies.

US Patent:

56438435, Jul 1, 1997

Filed:

Jul 12, 1996

Appl. No.:

8/678199

Inventors:

Stephen D. Dunmead - Midland MI
Alan W. Weimer - Midland MI
Daniel F. Carroll - Midland MI
Glenn A. Eisman - Midland MI
Gene A. Cochran - Midland MI
David W. Susnitzky - Midland MI
Donald R. Beaman - Midland MI
Kevin J. Nilsen - Midland MI

Assignee:

The Dow Chemical Company - Midland MI

International Classification:

C04B 35577
C04B 35596

US Classification:

501 92

Abstract:

Prepare silicon nitride-silicon carbide composite powders by carbothermal reduction of crystalline silica powder, carbon powder and, optionally, crystalline silicon nitride powder. The crystalline silicon carbide portion of the composite powders has a mean number diameter less than about 700 nanometers and contains nitrogen. The composite powders may be used to prepare sintered ceramic bodies and self-reinforced silicon nitride ceramic bodies.

US Patent:

54139724, May 9, 1995

Filed:

Dec 23, 1993

Appl. No.:

8/178377

Inventors:

Chinmau J. Hwang - Midland MI
Donald R. Beaman - Midland MI
David W. Susnitzky - Midland MI

Assignee:

The Dow Chemical Company - Midland MI

International Classification:

C04B 3558

US Classification:

501 98

Abstract:

A dense, substantially glass free, SiAlON ceramic material and method of making such material. The material has at least an alpha-SiAlON phase and a beta-SiAlON phase and exhibits excellent high temperature oxidation resistance and strength, good room temperature toughness and hardness, and a density greater than at least 95 percent of theoretical. The method of making the ceramic material is simple and includes adding AlN in an amount sufficient to allow formation of a desired amount of alpha-SiAlON, and in addition, convert SiO. sub. 2 and Al. sub. 2 O. sub. 3 into the beta-SiAlON phase, preferably, by adding AlN in an amount between about 1. 3X+0. 08Y-0. 0045XY and about 1. 3X+0. 2Y-0. 0024XY, wherein X is a weight percent of the SiO. sub. 2 based on total weight of the Si. sub. 3 N. sub.

US Patent:

55386750, Jul 23, 1996

Filed:

Apr 14, 1994

Appl. No.:

8/227751

Inventors:

Stephen D. Dunmead - Midland MI
Alan W. Weimer - Midland MI
Daniel F. Carroll - Midland MI
Glenn A. Eisman - Midland MI
Gene A. Cochran - Midland MI
David W. Susnitzky - Midland MI
Donald R. Beaman - Midland MI
Kevin J. Nilsen - Midland MI

Assignee:

The Dow Chemical Company - Midland MI

International Classification:

C01B 3100
C04B 3564

US Classification:

264 297

Abstract:

Silicon carbide/silicon nitride composites are prepared by carbothermal reduction of crystalline silica powder, carbon powder and optionally crsytalline silicon nitride powder. The crystalline silicon carbide portion of the composite has a mean number diameter less than about 700 nanometers and contains nitrogen.