Study of Phase Transformations in Ti Alloys

In this work phase transformations in metastable β Ti-15Mo alloy were stud- ied using electrical resistivity measurements. The alloy was subjected to a solu- tion treatment at a temperature higher than β-transus and quenched in water. In this condition, the microstructure of Ti-15Mo alloy consists of a metastable β-matrix and ω phase particles. During in-situ electrical resistivity measurement in a specially designed furnace, significant temperature points which indicate phase transformations in the material were detected. The dependence of elec- trical resistivity on the temperature changes during heating between increasing and decreasing according to the ongoing phase transformation. The changes were observed at temperatures 225, 356 and 560 ◦ C. A further study of these phase transformations using electrical resistivity measurements was performed on var- ious heat treated specimens. In order to control the microstructure evolution in the material, scanning and transmission electron microscopy was used. Mecha- nical properties were studied using Vickers microhardness testing. The obtained results serve to identify the type and sequence of phase transformations which take place in the Ti-15Mo alloy