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:
Mar. 08, 1988
Filed:
Jun. 30, 1986
Robert J Henricks, Farmington, CT (US);
John J Marcin, Hartford, CT (US);
Jacqueline B Wahl, Willington, CT (US);
United Technologies Corporation, Hartford, CT (US);
Abstract
A coated nickel base superalloy single crystal turbine airfoil blade (1), which is subject to gas turbine engine operation, can crack during refurbishment by a stress corrosion mechanism when exposed to certain corrosive media. The rapid thermal cycling that occurs during typical gas turbine engine operation results in high, non-uniform stresses across the airfoil, producing large localized residual strains in the article at ambient temperatures. Exposure to a corrosive environment, such as during coating removal or agressive cleaning, can produce chordwise cracks in a large number of the airfoils exposed. Such cracking is avoided by subjecting the articles to a preliminary stress relieving heat treatment which reduces the residual strains to a level below which cracking will not occur, prior to exposure to the corrosive media.