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:
Jul. 19, 1988
Filed:
Aug. 07, 1987
Frederick J Parker, Columbia, MD (US);
W. R. Grace & Co., New York, NY (US);
Abstract
A low thermal expansion ceramic composition having a predominant Al.sub.2 TiO.sub.5 phase along with zirconium titanate and zirconia phases. The final overall ceramic composition after firing has a low thermal expansion between 24.degree.-1000.degree. C. of not greater than 1.5.times.10.sup.-6 .degree. C..sup.-1 and a thermal stability in air such that (a) upon heating to 1200.degree. C. for at least 4 hours there is substantially no decomposition of the Al.sub.2 TiO.sub.5 phase to rutile or alumina as measured by X-ray diffraction, (b) physical growth after thermal cycling between 200.degree. and 1150.degree. C. for 300 cycles does not exceed 1.5%, and (c) the composition maintains a low average thermal expansion between 24.degree.-1000.degree. C. of not greater than 1.5.times.10.sup.-6 .degree. C..sup.-1 after the isothermal heating or cycling conditions. The composition is preferably made by forming a mixture of the equivalent of 50-90 volume percent Al.sub.2 TiO.sub.5 or a solid solution having a substantial amount of Al.sub.2 TiO.sub.5 in the solid solution, and zirconium titanate and then heating the mixture at a temperature of 1250.degree. C. or higher.