Ohio Aerospace Institute

The United States of America As Represented by the Administrator of the

Sverdrup Technology, Inc.

Mohan G Hebsur

Carl E Lowell

Joseph R Stephens

John D Whittenberger

A bond coat composition for use in thermal barrier coatings comprises a NiAl&mdash;CoCrAlY matrix containing particles of AlN dispersed therein. The bond coat composition is prepared by croymilling NiAl and CoCrAlY in liquid nitrogen.

Oxidation resistant and low coefficient of thermal expansion Nia1-CoCrAly alloy

Oxidation resistant and low coefficient of thermal expansion NiAl-CoCrAlY alloy

Oxidation resistant and low coefficient of thermal expansion NiA1-CoCrAly alloy

A MoSi pest resistant material includes in-situ grown &bgr;-Si N whiskers. In addition to excellent pest resistance, the material provides a lower coefficient of thermal expansion for better match with continuous reinforcing fibers such as SiC fibers. A two stage heating and pressing production technique enables lower temperature processing with substantially full densification.

Pest resistant MoSi2-based materials containing in-situ grown &bgr;-Si3N4 whiskers

A MoSi,pest resistant material includes in-situ grown &bgr;-Si,N,whiskers. In addition to excellent pest resistance, the material provides a lower coefficient of thermal expansion for better match with continuous reinforcing fibers such as SiC fibers. A two stage heating and pressing production technique enables lower temperature processing with substantially full densification.

Pest resistant MoSi2-based materials containing in-situ grown &bgr;-Si3N4whiskers

A particulate reinforced NiAl-AlN composite alloy has a NiAl matrix and greater than about 13 volume percent fine particles of AlN within the matrix. The particles preferably have a diameter from about 15 nanometers to about 50 nanometers. The particulate reinforced NiAl-AlN composite alloy may be prepared by cryomilling prealloyed NiAl in liquid nitrogen using grinding media having a diameter of from about 2 mm to about 6 mm at an impeller speed of from about 450 RPM to about 800 RPM. The cryomilling may be done for a duration of from about 4 hours to about 20 hours to obtain a cryomilled powder. The cryomilled powder may be consolidated to form the particulate reinforced NiAl-AlN composite alloy. The particulate reinforced alloy can further include a toughening alloy. The toughening alloy may include NiCrAlY, FeCrAY and FeAl.

Nial-base composite containing high volume fraction of AlN for advanced

A pest resistant molybdenum disilicide composition is provided for use in high temperature structural applications. The composition includes molybdenum disilicide and silicon nitride and can be used to prepare improved reinforced composites.

Pest resistant MoSi.sub.2 materials and method of making

A niobium-aluminum base alloy having improved oxidation resistance at high temperatures and consisting essentially of 48%-52% niobium, 36%-42% aluminum, 4%-10% chromium, 0%-2%, more preferably 1%-2%, silicon and/or tungsten with tungsten being preferred, and 0.1%-2.0% of a rare earth selected from the group consisting of yttrium, ytterbium and erbium. Parabolic oxidation rates, k.sub.p, at 1200.degree. C. range from about 0.006 to 0.032 (mg/cm.sup.2).sup.2 /hr. The new alloys also exhibit excellent cyclic oxidation resistance.

Growing community of inventors

North Olmsted, OH, United States of America

Mohan G Hebsur