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:
Oct. 06, 1992
Filed:
Sep. 07, 1990
Kenichiro Shibata, Itami, JP;
Hiroshi Nakamura, Itami, JP;
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
A polycrystalline spinel sintered body is provided herein which is superior in light transmission, such that it can be used in an infrared light-transmitting window at a thickness of 2 mm or more. The present invention also provides a method of producing such light-transmitting spinel sintered body by hot pressing the spinel powders having high purity at temperatures of 1,200.degree. to 1,700.degree. C. and pressures of 100 to 500 kg/cm.sup.2 to compact the sintered body until a density of 95% relative to the theoretical density is achieved and then subjecting the thus sintered compact to a hot isostatic pressure treatment at temperatures of 1400.degree. to 1800.degree. C. and pressures of 500 kg/cm.sup.2 or more. Other variations of this basic method can be employed as disclosed in the specification. According to Applicants' method, a sintered body of high density and excellent light transmission can be achieved which is superior to prior art methods.