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. 28, 2017
Filed:
Feb. 25, 2016
Denso Corporation, Kariya, Aichi-pref., JP;
DENSO CORPORATION, Kariya, JP;
Abstract
An alumina sintered body has a main phase made of alumina crystals, a first dispersed phase made of MgAlOdispersed in the main phase, and a second dispersed phase made of SiOand/or CaO dispersed in the main phase. A content ratio of the main phase is within a range from not less than 98% to less than 98%. The alumina sintered body satisfies a relationship of 100×I/I≧5.5%, where Iindicates a maximum peak height intensity derived from alumina, and Iindicates a maximum peak height intensity derived from MgAlOin a X-ray diffraction of the alumina sintered body. An area ratio of the second dispersed phase on a surface of the alumina sintered body is not more than 15.2%. A spark plug has a central electrode, a ground electrode and an insulator made of the alumina sintered body having the specific features previously described.