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:
Apr. 17, 2012
Filed:
Sep. 11, 2007
Applicant:
George C. Wei, Weston, MA (US);
Inventor:
George C. Wei, Weston, MA (US);
Assignee:
OSRAM SYLVANIA Inc., Danvers, MA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C30B 1/02 (2006.01);
U.S. Cl.
CPC ...
Abstract
Polycrystalline alumina (PCA) that has been doped with magnesium oxide is converted to sapphire by additionally doping the PCA with boron oxide and sintering to induce abnormal grain growth. The boron oxide may be added to an already formed green PCA ceramic shape by applying an aqueous boric acid solution to the green ceramic and heating the green ceramic in air to convert the boric acid to boron oxide.