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Microstructures and Mechanical Properties of Ti-48Al-2Cr-2Nb-xW

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Abstract:

The microstructures and mechanical properties of three powder metallurgy Ti-48Al-2Cr- 2Nb-xW alloys (where x=0, 0.5, and 1 atomic percent (at.%)) are presented. The results indicate that a solution heat treatment combined with controlled cooling generate a fully lamellar (FL) microstructure without the formation of detrimental Widmanstätten or massively transformed γ phases. Aging causes coarsening of the FL microstructure in the alloys containing 0%W and 0.5%W, while almost no coarsening occurs in the 1%W sample. The addition of W to the base composition results in the formation of precipitates at the lamellar interfaces and grain boundaries during aging which helps stabilize the FL microstructure. The amount of W and the aging time affect the room temperature hardness values and tensile properties.

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Periodical:

Materials Science Forum (Volumes 561-565)

Pages:

481-486

DOI:

https://doi.org/10.4028/www.scientific.net/MSF.561-565.481

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Online since:

October 2007

Authors:

Dongyi Seo, S. Bulmer, H. Saari, Peter Au

Keywords:

Lamellar Degradation, Precipitation, Tensile Properties, TiAl, Titanium Aluminide

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© 2007 Trans Tech Publications Ltd. All Rights Reserved

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