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. 25, 1986
Filed:
Aug. 25, 1983
Applicant:
Inventor:
David Mills, Bristol, GB;
Assignee:
Rolls-Royce Limited, Bristol, GB;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B22D / ;
U.S. Cl.
CPC ...
164131 ; 164132 ;
Abstract
Cores made from Alumina and other non-Silica based refractories can be made readily leachable in fused anhydrous caustic alkalis by the addition to the core of a small quantity of a material containing a Hydrogen donor group. The Hydrogen donor group is one which produces uncombined, or nascent Hydrogen when the ceramic is contacted with the anhydrous caustic alkali. Such groups are Hydroxyl groups, Hydrides or chemically combined water. In one disclosed example Silica which contains traces of water is added to high fired Alumina to provide the Hydrogen donor group. Only 2% to 3% Silica addition is required to make the Alumina readily soluble in the fused alkali.