Influence of interfacial reactions on the fiber-matrix interfacial shear strength in sapphire fiber-reinforced NiAl(Yb) composites

Journal Article · Wed Feb 01 00:00:00 EST 1995 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

DOI:https://doi.org/10.1007/BF02664684· OSTI ID:6604769

Tewari, S N; Smith, J ^[1]; Asthana, R; Bowman, R R ^[2]; Tiwari, R ^[3]

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1. Cleveland State Univ., OH (United States). Dept. of Chemical Engineering
2. NASA Lewis Research Center, Cleveland, OH (United States). Materials Division
3. UCAR Carbon Co., Cleveland, OH (United States)

The influence of microstructure of the fiber-matrix interface on the interfacial shear strength, measured using a fiber-pushout technique, has been examined in a sapphire-fiber-reinforced NiAl(Yb) matrix composite under the following conditions: (1) as-fabricated powder metallurgy (PM) composites, (2) PM composites after solid-state heat treatment (HT), and (3) PM composites after directional solidification (DS). The fiber-pushout stress-displacement behavior consisted of an initial pseudoelastic'' region, wherein the stress increased linearly with displacement, followed by an inelastic'' region, where the slope of the stress-displacement plot decrease until a maximum stress was reached, and the subsequent gradual stress decreased to a frictional'' stress. Energy-dispersive spectroscopy (EDS) and X-ray analyses showed that the interfacial region in the PM NiAl(Yb) composites was comprised of Yb[sub 2]O[sub 3], O-rich NiAl and some spinel oxide (Yb[sub 3]Al[sub 5]O[sub 12]), whereas the interfacial region in the HT and DS composites was comprised mainly of Yb[sub 3]Al[sub 5]O[sub 12]. A reaction mechanism has been proposed to explain the presence of interfacial species observed in the sapphire-NiAl(Yb) composite. The extent of interfacial chemical reactions and severity of fiber surface degradation increased progressively in this order: PM < HT < DS.

• OSTI ID: 6604769
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States), Vol. 26:2; ISSN 0360-2133
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
MICROSTRUCTURE
SHEAR PROPERTIES
ALUMINIUM OXIDES
COMPOSITE MATERIALS
INTERFACES
NICKEL ALLOYS
EXPERIMENTAL DATA
INTERMETALLIC COMPOUNDS
YTTERBIUM OXIDES
ALLOYS
ALUMINIUM COMPOUNDS
CHALCOGENIDES
DATA
INFORMATION
MATERIALS
MECHANICAL PROPERTIES
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
RARE EARTH COMPOUNDS
YTTERBIUM COMPOUNDS
360603* - Materials- Properties
360602 - Other Materials- Structure &amp; Phase Studies