The effect of processing and microstructure on properties of Ti-47Al-3Nb-1W and 46Al-2.5Nb-2Cr-0.2B {gamma} titanium aluminides
- AlliedSignal Engines, Stratford, CT (United States)
- Wyman-Gordon Co., Houston, TX (United States)
Two {gamma} aluminide compositions 47Al-3Nb-1W (at.%) and 46Al-2.5Nb-2Cr-0.2B (at.%) were examined for tensile and creep properties in lamellar, necklace and fine-grained microstructural conditions. The necklace microstructure was generated by decorating previously fully transformed lamellar colony boundaries with finely recrystallized grains through deformation. The lamellar microstructure showed the characteristic high creep resistance in both alloys. In the 47Al-3Nb-1W alloy, the lamellar microstructure showed low at room temperature ({approximately}0.5% elongation) and only the necklace microstructure provided a method to balance creep resistance (e.g., at 760 C) and room temperature ductility. In the 46Al-2.5Nb-2Cr-0.2B alloy, the B addition gave a definitive advantage to the lamellar microstructure by refining the colony size to {approx}0.1-0.2 mm which achieved improved room temperature ductility (e.g., {approximately}1.7% elongation relative to {approximately}0.5% typical in coarse lamellar microstructure). This microstructure provided creep resistance at 760 C, which, otherwise, was not attainable in fine-grained or necklace microstructures.
- OSTI ID:
- 225153
- Report Number(s):
- CONF-950201--; ISBN 0-87339-304-X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Creep of a fine-grained, fully-lamellar, two-phase TiAl alloy at 760{degree}C
Development of Ultrafine, Lamellar Structures in Two-Phase {gamma}-TiAl Alloys
Related Subjects
36 MATERIALS SCIENCE
AEROSPACE INDUSTRY
ALUMINIUM ALLOYS
BORON ADDITIONS
CASTING
CHEMICAL COMPOSITION
CHROMIUM ALLOYS
CREEP
DUCTILITY
EXPERIMENTAL DATA
FORGING
GRAIN GROWTH
GRAIN SIZE
HEAT TREATMENTS
HOT PRESSING
INTERMETALLIC COMPOUNDS
LAMELLAE
MATERIALS
MECHANICAL PROPERTIES
MICROSTRUCTURE
NIOBIUM ALLOYS
TENSILE PROPERTIES
THERMOMECHANICAL TREATMENTS
TITANIUM ALLOYS
TUNGSTEN ALLOYS