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:
Dec. 14, 1999
Filed:
Mar. 06, 1998
Melvin Robert Jackson, Niskayuna, NY (US);
Ann Melinda Ritter, Albany, NY (US);
Michael Francis Gigliotti, Jr, Scotia, NY (US);
General Electric Company, Schenectady, NY (US);
Abstract
A bond coat (20) of a thermal barrier coating system for components designed for use in a hostile thermal environment, such as turbine, combustor and augmentor components of a gas turbine engine. The composition of the bond coat (20) has graded thermal expansion properties that moderate the transition between a metal substrate (10) and a thermal-insulating ceramic layer (12) of a TBC protecting the substrate (10), while also reducing the service temperature of the bond coat (20) so as to reduce its rate of oxidation. Preferably, the bond coat (20) has multiple layers (20a, 20b, 20c), with the coefficients of thermal conductivity of the individual bond coat layers (20a, 20b, 20c) being very close to that of the substrate (10) in order to promote heat transfer from the outward layer (20c) of the bond coat (20) to the substrate (10). By minimizing the service temperature of the bond coat (20) while grading the thermal expansion properties through the coating system, a more spall-resistant coating system is achieved. The inward layer (20a) of the bond coat (20) preferably contains a metallic constituent, such as an aluminum and/or chromium-containing intermetallic, MCrAl and/or MCrAlY, a middle layer (20b) of the bond coat (20) also contains the metallic constituent in addition to a chromium phase, and an outward layer (20c) of the bond coat (20) contains the chromium phase and at least one platinum-containing phase. The middle and outermost layers (20b, 20c) may also contain chromium carbides such as Cr.sub.3 C.sub.2.