Fiber strength and fiber/matrix bond strength in single crystal Al[sub 2]O[sub 3] fiber reinforced Ni[sub 3]Al based composites

Journal Article · Wed Jun 01 04:00:00 EDT 1994 · Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States)

OSTI ID:7174407

Nourbakhsh, S; Rhee, W H; Sahin, O; Margolin, H ^[1]

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1. Polytechnic Univ., Brooklyn, NY (United States). Dept. of Materials Science and Engineering

A series of single-crystal Al[sub 2]O[sub 3] fiber (Saphikon), reinforced Ni[sub 3]Al-based composites were fabricated by a liquid metal infiltration technique, pressure casting. Tensile testing and indentation techniques have been employed to measure fiber strength and fiber/matrix interfacial debond shear stress. The Weibull mean strength of the fiber has been observed to decrease drastically upon handling, exposure to high temperature, and casting. Alloying of Ni[sub 3]Al with Ti has resulted in a further decrease in fiber strength. Thermal expansion mismatch between the fiber and matrix led to the formation of compressive twins in the fiber. These twins, forming on [l brace][bar 1]102[r brace] planes, produced cracks at their intersections, which were parallel to the fiber axis, c-axis. Twin-induced fiber cracking was observed in all cases, but most predominantly when Cr was present. While addition of Cr at the 1 at. pct level-had no appreciable effect on the interfacial debond shear stress, addition of 0.5 at. pct Cr resulted in an approximately threefold increase in debond stress, from 19 MPa to about 54.5 MPa. Alloying of Ni[sub 3]Al with Cr has also resulted in partial dissolution of the Al[sub 2]O[sub 3] fiber. Addition of Ti had a moderate effect on increasing the fiber/matrix bond strength.

• OSTI ID: 7174407
• Journal Information: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States), Journal Name: Metallurgical Transactions, A (Physical Metallurgy and Materials Science); (United States) Vol. 25:6; ISSN 0360-2133; ISSN MTTABN
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CHROMIUM
CHROMIUM ADDITIONS
CHROMIUM ALLOYS
COMPOSITE MATERIALS
CRACK PROPAGATION
DATA
ELEMENTS
EXPERIMENTAL DATA
FIBERS
INFORMATION
INTERFACES
MATERIALS
MECHANICAL PROPERTIES
METALLURGICAL EFFECTS
METALS
NICKEL ALLOYS
NICKEL BASE ALLOYS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
SHEAR PROPERTIES
TENSILE PROPERTIES
TITANIUM
TRANSITION ELEMENTS