FGMs by sedimentation

Book · Tue Dec 31 04:00:00 EST 1996

OSTI ID:490761

He, Y; Subramanian, V; Lannutti, J ^[1]

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1. Ohio State Univ., Columbus, OH (United States)

Simple sedimentation in organic solvents followed by hot-pressing is used to produce alumina-NiAl functionally graded materials (FGMs). Varying degrees of agglomeration influenced the phase arrangement in the mixed layer(s) producing microstructural variation. The authors discovered a pronounced structural dependence on NiAl stoichiometry. Slight variations in Al content are known to influence T{sub db} and these apparently lead to large increases in residual stress. Zirconia-NiAl FGMs were better able to accommodate these levels of residual stress possibly due to accommodation by enhanced tetragonal phase retention. However, these FGMs undergo transformation of the tetragonal phase to the monoclinic form, starting from the surface. Finally, variable microstructures result in detectable changes in the stress-strain behavior of alumina-NiAl FGMs. 47 refs., 11 figs.

• Sponsoring Organization: Office of Naval Research, Washington, DC (United States)
• OSTI ID: 490761
• Report Number(s): CONF-960401--; ISBN 1-55899-337-1
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
ALUMINIUM OXIDES
BULK DENSITY
COMPOSITE MATERIALS
EXPERIMENTAL DATA
FABRICATION
HOT PRESSING
LAYERS
MECHANICAL PROPERTIES
MICROSTRUCTURE
NICKEL ALLOYS
PHASE TRANSFORMATIONS
POWDERS
SEDIMENTATION
STRESSES
ZIRCONIUM OXIDES