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:
May. 01, 1979
Filed:
Jul. 21, 1978
Peter H Havstad, Livonia, MI (US);
Ford Motor Company, Dearborn, MI (US);
Abstract
A method is disclosed for predicting the service life of silicon nitride material under operating conditions of a ceramic turbine engine in whch an article is subjected to high temperatures under oxidizing conditions. The method for selecting a silicon nitride article to be used under these high temperature oxidizing conditions is generally as follows. A determination is made of the weight gain of a silicon nitride article under oxidizing conditions for a testing period of at least 12 hours at a temperature in the range from about 1800.degree. F. (932.degree. C.) to about 2500.degree. F. (1371.degree. C.). The weight gain determination is made after the silicon nitride article has been manufactured, and prior to its being subjected to any previous high temperature oxidizing conditions. The weight the silicon nitride article would gain at a projected time, which is a number of hours greater than the testing period, is empirically determined from the weight gain determinations made in the testing period. The silicon nitride article is accepted or rejected for further use under high temperature oxidizing conditions based upon the empirically determined weight gain at the projected time. For example, if the amount of weight gained at the projected time is too great, the article is rejected as being one which will not have a long life under high temperature oxidizing conditions.