Superplastic behavior and deformation mechanism of Ti600 alloy

Abstract

The superplastic deformation behavior and mechanism of Ti600 alloy at elevated temperature were investigated. Results show that Ti600 alloy exhibits excellent superplastic behavior in the temperature range of 840–960°C at 5×10−4s−1 and all of the tensile elongations exceed 220%. Optical microstructure shows that the grains still remain equiaxed and refined after deformation. However, primary α phase increases with the increasing of temperature. TEM observation indicates that the intragranular dislocation movement is very active and is accompanied by the occurrence of dynamic recrystallization, which is beneficial to promote the grainboundary sliding and to relieve the stress concentration. The superplastic deformation mechanism of Ti600 alloy is grainsgroup sliding accommodated by dislocation movement and dynamic recrystallization. The model of this mechanism is a corrected Ball–Hutchinson Model.