Hot deformation behaviours of Ti-1100/0.1Y alloy through isothermal hot compression tests

Hot deformation behaviours of Ti-1100 alloy adding 0.1% (mass) yttrium were studied by thermal simulator in the temperature range 990-1100°C and strain rate range 0.001-10 s^-1. The deformation map during hot working and good processing performance field are established. The microstructures were observed by optical microscope. The experimental results indicate that the variation of deformation temperature does not change the characteristics of true stress- strain curves but the variation of strain rate has crucial effect on the deformation map. The instable flow happens at strain rate 10 s^-1, β phase dynamic recrystallization at 0.1-1 s^-1 and dynamic recovery at 0.001-0.01 s^-1. Considering workability and microstructure refining, the optimum conditions for Ti-1100/0.1Y alloy hot deformation are found out in the temperature range 990-1020°C and strain rate range 0.01-1 s^-1.