Stress-strain behavior of lamellar Ti-38Al-3Zr and -3Nb alloys with average lamellar thickness ranging from 10 to 1000nm were studied at room temperature. Their yield stresses decreased from a high value of coherent lamellar structures to a low value after introducing misfit dislocations onto lamellar boundaries. Their strain hardening rates increased with decreasing lamellar thickness, and then drop to a low level when the misfit dislocations become absent. There was critical thickness of γ lamellae for introduction of misfit dislocations. The thickness decreased with increasing lattice misfit between the constituent phases.

Effects of Lamellar Thickness on Misfit Dislocation Introduction and Mechanical Properties of γ/α2 Nano-Lamellar TiAl Alloys. K.Maruyama, A.Tabata, Y.Toriyama, M.Suzuki, K.Yoshimi: Journal of Physics - Conference Series, 2010, 240[1], 012101