Thermal strains in titanium aluminide and nickel aluminide composites

Conference · Tue Dec 31 23:00:00 EST 1991

OSTI ID:5160822

Saigal, A ^[1]; Kupperman, D S ^[2]

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1. Tufts Univ., Medford, MA (United States). Dept. of Mechanical Engineering
2. Argonne National Lab., IL (United States)

Neutron diffraction was used to measure residual thermal strains developed during postfabrication cooling in titanium aluminide and nickel aluminide intermetallic matrix composites. Silicon carbide /Ti 14Al-21Nb, tungsten and sapphire/NiAl, and sapphire and SiC-coated sapphire/NiAl{sub 25}Fe{sub 10} composites were investigated. The thermal expansion coefficient of the matrix is usually greater than that of the fibers. As such, during cooldown, compressive residual strains are generated in the fibers and tensile residual strains are generated in the matrix, parallel to the fibers. Liquid-nitrogen dipping and thermal cycling tend to reduce the fabrication-induced residual strains in silicon carbide-fiber-reinforced titanium aluminide matrix composites. However, matrix cracking can occur as a result of these processes. The axial residual strains in the matrix were lower in the nickel aluminide matrix than in the titanium aluminide matrix. As the matrix undergoes plastic deformation, residual thermal strains are related to the yield stress of the matrix.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5160822
• Report Number(s): ANL/CP-75762; CONF-920604--3; ON: DE92015181
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601 -- Other Materials-- Preparation & Manufacture
360603* -- Materials-- Properties
ALLOYS
ALUMINIUM ALLOYS
CARBIDES
CARBON COMPOUNDS
COHERENT SCATTERING
COMPOSITE MATERIALS
COOLING
CORUNDUM
DEFORMATION
DIFFRACTION
ELEMENTS
EXPANSION
FIBERS
INTERMETALLIC COMPOUNDS
MATERIALS
METALS
MINERALS
NEUTRON DIFFRACTION
NICKEL ALLOYS
NIOBIUM ALLOYS
OXIDE MINERALS
REINFORCED MATERIALS
RESIDUAL STRESSES
SAPPHIRE
SCATTERING
SILICON CARBIDES
SILICON COMPOUNDS
STRESSES
THERMAL EXPANSION
THERMAL STRESSES
TITANIUM ALLOYS
TRANSITION ELEMENTS
TUNGSTEN