Loss of coherency of the alpha/beta interface boundary in titanium alloys during deformation

Abstract

The loss of coherency of interphase boundaries in two-phase titanium alloys during deformation was analyzed. The energy of the undeformed interphase boundary was first determined by means of the van der Merwe model for stepped interfaces. The subsequent loss of coherency was ascribed to the increase of interphase energy due to absorption of lattice dislocations and was quantified by a relation similar to the Read–Shockley equation for low-angle boundaries in single-phase alloys. It was found that interphase boundaries lose their coherency by a strain of approximately 0.5 at T = 800°C.

Keywords:

• titanium alloys
• interfaces
• coherency
• plastic deformation

Acknowledgements

The authors express their thanks to Dr A. Belyakov, Belgorod State University, for providing useful advice and facilitating discussions. This study was supported by the Federal Agency for Science and Innovations, Grant No. 02.740.11.0510.