Properties of reactively synthesized titanium aluminides
- Bureau of Mines, Albany, OR (United States). Albany Research Center
Reactive synthesis directly forms compounds from their elemental constituents. In this US Bureau of Mines study the microstructure, hot-hardness and tensile properties of alloys and composites based on TiAl and Ti{sub 2}AlNb were studied. Ti{sub 2}AlNb sheets were processed from elemental Ti, Al and Nb foils. The elemental foils were consumed during processing, leaving a microstructure consisting of three phases: O (orthorhombic Ti{sub 2}AlNb), B2 (ordered cubic Ti), and {alpha}{sub 2} (Ti{sub 3}Al). The composite sheet structures were heat-treated to produce a microstructure consisting of O lathes in a B2 matrix. A significant advantage of reactive synthesis is the ease of formation of complex shapes prior to synthesis of the aluminide. TiAl-based alloys and in situ TiAl/boride and TiAl/Ti{sub 5}Si{sub 3} composites were produced from elemental mixtures of Ti and Al with either additions of B or Si powders. The hot-hardness and tensile properties of these alloys and composites are reported. The Kirkendall porosity associated with reactive sintering of TiAl can be eliminated by simultaneously reactive sintering TiAl and Ti{sub 5}Si{sub 3}.
- OSTI ID:
- 72479
- Report Number(s):
- CONF-941144--; ISBN 1-55899-265-0
- Country of Publication:
- United States
- Language:
- English
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