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. 16, 2019
Filed:
Oct. 12, 2017
The Government of the United States of America, As Represented BY the Secretary of the Navy, Arlington, VA (US);
James A. Wollmershauser, Alexandria, VA (US);
John Drazin, Alexandria, VA (US);
Dana A. Kazerooni, McLean, VA (US);
Boris N. Feigelson, Springfield, VA (US);
Edward P. Gorzkowski, III, Odenton, MD (US);
The United States of America, as represented by the Secretary of the Navy, Washington, DC (US);
Abstract
A process for producing metastable nanocrystalline alpha-alumina (α-AlO) having particle sizes smaller than 12 nm. Starting crystallites of α-AlOhaving a particle size larger than 12 nm, typically on the order of about 50 nm, are ball-milled at low temperatures to produce a nanocrystalline α-AlOpowder having a particle size of less than 12 nm, i.e., below the theoretical room temperature thermodynamic size limit at which α-AlOchanges phase to γ-AlO, wherein the powder remains in the α-AlOphase at all times.