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:
Sep. 20, 1988
Filed:
Jul. 06, 1987
William S Coblenz, Hudson, MA (US);
Paul J Pelletier, Thompson, CT (US);
Guilio A Rossi, Shrewsbury, MA (US);
Norton Company, Worcester, MA (US);
Abstract
Zirconia ceramics containing substantial amounts of metastable tetragonal phase crystallites, so that they are tougher than most other ceramics, can be completely comminuted to powders, without applying any mechanical force, by treatment with water or steam at temperatures well above room temperature. This type of comminution is particularly useful for small, often hollow, spheres produced by rapidly solidifying melts of zirconia and a stabilizing oxide such as yttria. These spheres can be almost completely comminuted to a size suitable for wet vibratory milling by treatment for twenty-four hours at 250 C under sufficient steam pressure to maintain some liquid water in equilibrium.