Thermal expansion evolution of metastable β Ti-15Mo alloy during linear heating

Abstract

Thermal expansion measurement was employed for characterization of phase transformations occurring in metastable β titanium alloy (Ti-15Mo) during linear heating with three different heating rates. Effects of the transformations on materials dimensions is discussed and compared with changes of lattice parameters of present phases obtained from in-situ powder neutron diffraction. The shrinkage of the material with increasing temperature at about 300 °C was attributed to the decrease of lattice parameter of β phase, which occurs due to diffusion of alloying elements out of ω phase. Complete dissolution of ω phase was detected at 560 °C regardless of the heating rate.