Dislocations in continuous filament reinforced W/NiAl and Al{sub 2}O{sub 3}/NiAl composites

Journal Article · Mon Dec 01 04:00:00 EST 1997 · Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science

DOI:https://doi.org/10.1007/s11661-997-0032-7· OSTI ID:590090

Wang, L ^[1]; Xu, K ^[2]; Bowman, R R ^[3]; Arsenault, R J ^[4]

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1. National Aeronautics and Space Administration, Greenbelt, MD (United States). Goddard Space Flight Center
2. National Inst. of Standard and Technology, Gaithersburg, MD (United States). Ceramics Div.
3. National Aeronautics and Space Administration, Cleveland, OH (United States). Lewis Research Center
4. Univ. of Maryland, College Park, MD (United States). Dept. of Materials and Nuclear Engineering

Continuous filament reinforced W/NiAl and Al{sub 2}O{sub 3}/NiAl composites (as-processed, annealed, and thermally cycled) have much higher dislocation densities than that of monolithic NiAl. These higher dislocation densities resulted from the relaxation of thermal residual stress, which developed during the cooling of the sample from elevated temperatures and was caused by the difference in the coefficients of thermal expansion between the matrix and the reinforcement. The dislocation density in the region adjacent to the matrix-filament interface was high and decreased only slightly with distance from the interface in the 30 vol pct composites. The as-processed and annealed composites exhibited a rather homogeneous dislocation density in the matrix. After thermal cycling, these composites showed no large difference in the dislocation density and morphology. However, there were local regions of lower dislocation densities. This difference was examined in relationship to filament fracture, surface matrix cracking, and degree of bonding.

• Sponsoring Organization: Office of Naval Research, Washington, DC (United States)
• OSTI ID: 590090
• Journal Information: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science, Journal Name: Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science Journal Issue: 12 Vol. 28; ISSN MMTAEB; ISSN 1073-5623
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
ALUMINIUM OXIDES
COMPOSITE MATERIALS
DEFORMATION
DISLOCATIONS
MORPHOLOGY
NICKEL ALLOYS
REINFORCED MATERIALS
TEMPERATURE DEPENDENCE
TUNGSTEN