United Technologies Corporation

Maurice L Gell

David N Duhl

Alan David Cetel

William Patrick Allen

Charles M Biondo

Anthony F Giamei

Daniel P DeLuca

Allan A Noetzel

Otis Y Chen

Abdus S Khan

John W Appleby, Jr

Bradford A Cowles

Richard S Mullin

Richard H Barkalow

Emanuel Collins Hirakis

Edward Joseph Felten

Stephen Thomas Magyar

Compositional requirements and processing improvements are disclosed which improve the hydrogen embrittlement resistance and the fatigue resistance in air of nickel base single crystal articles. The compositional requirements enlarge the difference between the &ggr;&prime; solvus temperature and the incipient melting temperature, thus enabling the solution of &ggr;/&ggr;&prime; eutectic islands without causing incipient melting, while hot isostatic pressing and careful melt practice eliminate porosity and carbides, borides and nitrides, all of which act as crack initiation sites.

Nickel base superalloy single crystal articles with improved performance in air and hydrogen

A thermal barrier coating for high temperature applications has improved resistance to heat flow. The coating comprises a large number of these (nanometer scale) layers separated by interfaces which are effective in retarding heat flow. The coating material will typically be oxide based ceramics and the coating has particular applications in gas turbine engines.

Multiple nanolayer coating system

A single crystal nickel base superalloy component, such as a gas turbine blade (20, 28) is mechanically deformed at elevated temperature to improve the yield strength of a portion which is used at temperatures below 800.degree. C., compared to a portion which is used at a higher temperature. A blade (20) has a root (22) which is deformed by 2-14% at 700.degree.-1100.degree. C. and an airfoil (24) which is not deformed. The root yield strength is increased 15-50% while the airfoil creep strength is maintained.

Mechanically worked single crystal article

Single crystal superalloy articles of a composition similar to that of IN-939 are given a combined coating and heat treatment cycle. The cycle includes a solution treatment step, a coating application step, a post coating treatment at a temperature above the gamma prime solvus and one or more aging steps. Articles so treated have improved mechanical properties.

Method for producing corrosion resistant high strength superalloy

Nickel base superalloy single crystal articles formed from an alloy family and heat treated are described as is the process employed. The articles are substantially free from cobalt and the grain boundary strengtheners such as carbon, boron, and zirconium. The heat treatment process homogenizes the microstructure, and refines the gamma prime morphology.

Heat treated superalloy single crystal article and process

Cobalt base alloys for use at elevated temperatures are disclosed that possess excellent resistance to oxidation/corrosion at elevated temperatures in combination with mechanical properties which exceed those of similar alloys currently in use. The resistance to oxidation/corrosion is afforded by a particular combination of aluminum and chromium which act to form a protective alumina layer and a synergistic combination of hafnium and yttrium which act to promote adherence of the alumina. Refractory metal additions are utilized to improve the mechanical properties. The alloys of the invention are suited for use in gas turbine engines as well as industrial applications such as furnaces and chemical process apparatus.

Oxidation resistant cobalt base alloy

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Newington, CT, United States of America

Maurice L Gell