INERTIAL EFFECTS IN PLASTICITY OF ALPHA-T ITANIUM AT LOW-TEMPERATURESUP TO 0.5 K

Detailed studies of the temperature dependences of yield strength, str ain rate sensitivity of deformation stress and activation volume have been carried out on alpha-titanium samples with oxygen content varying from 0.06 to 0.96 at. %. The presence of low temperature anomalies in the above parameters was confirmed. Using a strict procedure of the t hermoactivation analysis applied earlier to experimental data the theo retical parameters of low-temperature plasticity were estimated empiri cally for Ti-O interstitial solid solutions. The above anomalies are t hought to be associated with a change from the thermoactivation mechan ism of overcoming impurity barriers by dislocations to the thermoinert ial one in the vicinity the of threshold temperature T-i dependent on oxygen concentration. From the analysis of the dependence of T-i upon the impurity concentration, a simple empirical expression has been der ived for the temperature dependence of the dynamic drag coefficient of dislocations in the low-temperature range.