Internal friction in the commercial 2-phase α+β alloy was measured at 90 to 400K, using frequencies near to 1Hz. Two components of the internal friction were observed in specimens which had been quenched from temperatures near to the α/β transus at 1173K. One component was a well-defined peak at 120K, and the other was a broader peak near to 200K. The magnitude of the former peak was increased by H-charging, and the activation energy was close to that for H diffusion in β-Ti. The peak was therefore attributed to the stress-induced redistribution of H atoms in the β-phase. The component at 200K appeared when the alloy had been quenched from temperatures near to the transus, but did not do so when it had been cooled slowly. It was suggested that this component was due either to defects in the martensite which was produced by quenching, or to the interfaces between the martensite and the β phase.

Low-Frequency Internal Friction of α+ β Titanium Alloy SP-700. X.S.Guan, H.Numakura, M.Koiwa, K.Hasegawa, C.Ouchi: Materials Science and Engineering A, 1999, 272, 230-7