Microstructures and Mechanical Properties of Ti-48Al-2Cr-2Nb-xW
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.
Young Won Chang, Nack J. Kim and Chong Soo Lee
D. Y. Seo et al., "Microstructures and Mechanical Properties of Ti-48Al-2Cr-2Nb-xW", Materials Science Forum, Vols. 561-565, pp. 481-486, 2007