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Texture Formation in High Niobium Containing TiAl Alloys
Published online by Cambridge University Press: 26 February 2011
Abstract
Texture formation was studied in high Nb bearing g-TiAl based alloys with compositions of Ti-45Al-(5,7.5,10)Nb-(0,0.5)C (compositions are in atomic percent). In order to start with texture-free material hot-isostatically pressed powder compounds were used. The deformation was performed either in uniaxial compression or by hot rolling. After compression at 700 °C and 800 °C fiber textures with <110> and <302> components occur. These deformation textures can be verified by computer simulations using a yield surface model of g-TiAl. With higher deformation temperatures the <110> fiber vanishes and new accumulations of orientations are formed, which are due to dynamic recrystallization.
Hot rolling was performed at temperatures in the upper part of the (a+g) phase field and, therefore, with more than 50% a-phase existing. The co-deformation of a- and g-phase during rolling leads to correlated components in the independently measured textures of both phases. The texture of the g-phase shows a maximum of orientation around the Goss2 component and the texture of the a-phase exhibits an orientation maximum around the transversal component. The correlation is the Blackburn orientation relation, although the textures are not caused by phase transformations, but by co-deformation. Hot rolling with many passes and reheating between the passes lead to the formation of a cube component with an alignment of the c-axes in transverse direction. In general, this is a typical recrystallization-induced component in hot rolled TiAl.
Keywords
- Type
- Research Article
- Information
- MRS Online Proceedings Library (OPL) , Volume 980: Symposium II – Advanced Intermetallic-Based Alloys , 2006 , 0980-II07-01
- Copyright
- Copyright © Materials Research Society 2007
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