Kinetics of the phase transformation in a Ti-15Mo-5Zr-3Al alloy as studied by X-ray diffraction

The purpose of the study is to make the T-T-T diagram available and to describe the X-ray diffraction techniques used to determine the fraction of transformed phase in the Ti-15Mo-5Zr-3Al metastable beta-alloy which decomposes into the hexagonal alpha-phase and the bcc beta-phase of a higher Mo concentration. The sheet material studied for this study is not ideal for an X-ray examination because of both a rolling and annealing texture as well as grain size problems. These difficulties are overcome using special X-ray techniques. Equations are given that indicate the approximations to be accepted if pole figure data are disregarded. Lattice parameter data from the beta phase enables one to obtain an approximate phase diagram.