A new methodology for identification of β-transus temperature in α + β and β titanium alloys using ultrasonic velocity measurement

A new methodology has been established for identification of β-transus temperature in α + β and β titanium alloys by ultrasonic velocity measurements in a single specimen in one microstructural condition only. This methodology is based on a linear correlation obtained for the variation in β-transus temperature with ultrasonic longitudinal wave velocity in various titanium alloys specimens, β-heat-treated followed by water quenching. Furthermore, it has been demonstrated for the first time that ultrasonic velocity in α′ martensitic structure increases with the addition of α-stabilizing elements and decreases with the addition of β-stabilizing elements for α + β titanium-alloys. Acknowledgments We thank Dr. T. K. Nandy and Dr. A. Bhattacharjee, Defence Metallurgical Research Laboratory (DMRL), Hyderabad, India; M. Narayana Rao, Mishra Dhatu Nigam Limited (earlier with Nuclear Fuel Complex), Hyderabad and Dr. U. Kamachi Mudali, Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, for providing various titanium alloys and also for useful discussions. We are also thankful to S. Mahadevan, NDE Division, IGCAR for the X-ray diffraction studies and Dr. K. Chandrasekhar, DMRL, Hyderabad for chemical analysis of the specimens.