Effect of Surface Modification of α-Ti on Internal Friction

The measurements of the internal friction were done using the RAK -3 relaxator at the bending mode oscillation of the acoustic frequency. The annealed α-Ti and α-Ti with the surface modified by the pulse mechanical grinding, by the plasma assisted formation of the layer of Ti-Al intermetallics and by the electrochemical hydrogen charging have been studied. The Young modulus and the attenuation of samples were measured at the heating of specimens between 200 and 600 K. In the studied temperature range, some relaxation processes occurred in the modified specimens. The values of the Young modulus and of the internal friction background have been also found to depend on the state of the Ti surface. The possible effects of the phase composition and the stress state on the obtained results have been discussed.