Microstructural stability of directionally solidified eutectic NiAl-Mo under static and thermal cycling conditions

Book · Wed Dec 31 04:00:00 EST 1997

OSTI ID:571818

Kush, M T; Holmes, J W; Gibala, R ^[1]

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1. Univ. of Michigan, Ann Arbor, MI (United States)

The quasi-binary eutectic NiAl-9% Mo with faceted molybdenum fibers was subjected to both thermal annealing conditions and to annealing under thermal cycling conditions to determine the microstructural stability of this alloy. The static temperature tests were run at 0.85T{sub M}--0.97T{sub M} in an argon gas atmosphere. The thermal cycling tests were performed between temperatures of 700 C and 1,200 C by induction heating disk-shaped specimens in an argon gas atmosphere using time-temperature heating and cooling profiles to approximate potential engine applications. To quantify microstructural changes, the fiber size and size distribution and number of fibers per unit area were measured as a function of time at temperature. The overall results demonstrate that the directionally solidified eutectic NiAl-9Mo subjected to thermal fatigue conditions exhibits cell boundary coarsening and large shape changes, whereas the microstructure under static stress-free annealing is stable.

• OSTI ID: 571818
• Report Number(s): CONF-961202--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
COMPOSITE MATERIALS
EXPERIMENTAL DATA
FIBERS
INTERMETALLIC COMPOUNDS
MICROSTRUCTURE
MOLYBDENUM ALLOYS
NICKEL ALLOYS
THERMAL FATIGUE