The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 22, 2000
Filed:
Sep. 22, 1998
Tudor C Gheorghiu, Painted Post, NY (US);
Andreas Schmidt, Kaiserslautern, DE;
Corning Incorporated, Corning, NY (US);
Abstract
A method of fabricating a cordierite ceramic honeycomb structural body which includes the following steps: formulating a batch of raw materials comprising a mixture of kaolin clay, talc, alumina and other cordierite-forming materials, each included in the batch in an effective amount such that the batch is capable of yielding a fired honeycomb body whose predominant crystal phase is cordierite; intimately blending the raw materials with an effective amount of vehicle and forming aids to impart plastic formability and green strength to the raw materials and to form a plastic mixture; forming the raw materials into a green honeycomb structural body by extrusion and thereafter drying and firing the green honeycomb structural body. The firing of the green honeycomb structural body is accomplished through a four-phase heating process as follows (1) heating the green body to a first temperature ranging between about 750-850.degree. C.; (2) heating to a second temperature ranging between about 1250 to 1350.degree. C.; and finally, (3) to a third temperature of at least 1390.degree. C., and (4) maintaining a temperature of at least 1390 but less than 1420.degree. C., for a period of about 12 to 20 hours. In one embodiment, an oxidizing firing atmosphere, comprising no greater than about 6% O.sub.2, is maintained at firing temperatures above the first temperature. Alternatively, a reducing as opposed to an oxidizing, firing atmosphere, comprising no greater than about 3% CO, is maintained at firing temperatures above the first temperature.