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:
Jun. 06, 1989
Filed:
Jun. 04, 1987
Gregory R Frank, Muskegon, MI (US);
Kenneth A Canfield, Whitehall, MI (US);
Thomas R Wright, Muskegon, MI (US);
Howmet Corporation, Greenwich, CT (US);
Abstract
A ceramic core for use in the investment casting of metals includes, prior to sintering, about 80 w/o to about 86 w/o of a ceramic filler material and about 14 w/o to about 20 w/o of a binder material. The ceramic filler material includes about 66 w/o to about 95 w/o Al.sub.2 O.sub.3 particles, about 1 w/o to about 20 w/o Y.sub.2 O.sub.3 particles, about 1 w/o to about 5 w/o of a grain growth inhibiting agent, and the balance a carbon-bearing fugitive filler material. Subsequent to sintering, the ceramic core has a microstructure characterized by the presence of substantially unreacted Al.sub.2 O.sub.3 particles having a polycrystalline composition consisting essentially of 3Y.sub.2 O.sub.3.5Al.sub.2 O.sub.3 on the surfaces of the Al.sub.2 O.sub.3 particles.