Abstract: 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;′ solvus temperature and the incipient melting temperature, thus enabling the solution of &ggr;/&ggr;′ 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.