Interfacial strengthening of β phase in a fully lamellar structure of TiAl alloy containing W

Abstract The strengthening of the β phase in two fully lamellar structures with different lamellar spacing of a Ti–48 at.% Al–2 W at.% alloy during creep deformation has been investigated. It was found that the β phase precipitates during aging treatments only within regions of α2 lamellae following their dissolution. The strengthening of the β phase is more effective in the coarser lamellar structure, because the wider β precipitation zones, which replace the prior coarser α2 lamellae, hinders dislocation motion stronger than the narrower ones. Acknowledgements Financial support from the 21st century COE program in Tohoku University Materials Research Center and the Ministry of Education, Science, Sports and Culture, Japan (Grant No. 17360309) is gratefully acknowledged. The Canadian Department of National Defence also supported this research. The authors acknowledge Mr. Y. Kondo for his technical assistance with the TEM analysis.