Paul M Pelletier

US Patent:

49256084, May 15, 1990

Filed:

Sep 27, 1988

Appl. No.:

7/249791

Inventors:

Guilio A. Rossi - Shrewsbury MA
Paul J. Pelletier - Thompson CT

Assignee:

Norton Company - Worcester MA

International Classification:

C04B 3556

US Classification:

264 60

Abstract:

A method of joining two pre-sintered pieces of silicon carbide is disclosed. It entails polishing the surfaces to be joined to a mirror-finish, fitting the polished surfaces together to form a composite structure, and then subjecting the composite structure to hot isostatic pressing under conditions which are sufficient to form a joint which is essentially indistinguishable from the original silicon carbide pieces.

US Patent:

49215540, May 1, 1990

Filed:

Sep 27, 1988

Appl. No.:

7/250018

Inventors:

Carl H. Bates - Worcester MA
John T. Couhig - Worcester MA
Paul J. Pelletier - Thompson CT

Assignee:

Norton Company - Worcester MA

International Classification:

B32B 1800

US Classification:

156 89

Abstract:

A method of joining two porous bodies of silicon carbide is disclosed. It entails utilizing an aqueous slip of a similar silicon carbide as was used to form the porous bodies, including the sintering aids, and a binder to initially join the porous bodies together. Then the composite structure is subjected to cold isostatic pressing to form a joint having good handling strength. Then the composite structure is subjected to pressureless sintering to form the final strong bond. Optionally, after the sintering the structure is subjected to hot isostatic pressing to further improve the joint and densify the structure. The result is a composite structure in which the joint is almost indistinguishable from the silicon carbide pieces which it joins.

US Patent:

55717608, Nov 5, 1996

Filed:

Oct 18, 1994

Appl. No.:

8/324937

Inventors:

Vimal K. Pujari - Northboro MA
Dennis M. Tracey - Medfield MA
Michael R. Foley - Oxford MA
Norman I. Paille - Oxford MA
Paul J. Pelletier - Millbury MA
Lenny C. Sales - Grafton MA
Craig A. Willkens - Sterling MA
Russell L. Yeckley - Oakham MA

Assignee:

Saint-Gobain/Norton Industrial Ceramics Corporation - Worcester MA

International Classification:

C04B 35587

US Classification:

501 97

Abstract:

A silicon nitride ceramic comprising: a) inclusions no greater than 25 microns in length, b) agglomerates no greater than 20 microns in diameter, and c) a surface finish of less than about 8 microinches, said ceramic having a four-point flexural strength of at least about 900 MPa.

US Patent:

47719508, Sep 20, 1988

Filed:

Jul 6, 1987

Appl. No.:

7/069735

Inventors:

William S. Coblenz - Hudson MA
Paul J. Pelletier - Thompson CT
Guilio A. Rossi - Shrewsbury MA

Assignee:

Norton Company - Worcester MA

International Classification:

B02C 1912

US Classification:

241 1

Abstract:

Zirconia ceramics containing substantial amounts of metastable tetragonal phase crystallites, so that they are tougher than most other ceramics, can be completely comminuted to powders, without applying any mechanical force, by treatment with water or steam at temperatures well above room temperature. This type of comminution is particularly useful for small, often hollow, spheres produced by rapidly solidifying melts of zirconia and a stabilizing oxide such as yttria. These spheres can be almost completely comminuted to a size suitable for wet vibratory milling by treatment for twenty-four hours at 250 C under sufficient steam pressure to maintain some liquid water in equilibrium.

US Patent:

57594813, Jun 2, 1998

Filed:

Oct 25, 1996

Appl. No.:

8/739107

Inventors:

Vimal K. Pujari - Northboro MA
Dennis M. Tracey - Medfield MA
Michael R. Foley - Oxford MA
Norman I. Paille - Oxford MA
Paul J. Pelletier - Sutton MA
Lenny C. Sales - Grafton MA
Craig A. Willkens - Worcester MA
Russell L. Yeckley - Latrobe PA

Assignee:

Saint-Gobain/Norton Industrial Ceramics Corp. - Worcester MA

International Classification:

C04B 35584

US Classification:

264655

Abstract:

A ceramic body comprising at least about 80 w/o silicon nitride and having a mean tensile strength of at least about 800 MPa.