Eleventh International Conference on Internal Friction and Ultrasonic Attenuation in Solids
J. Phys. IV France 06 (1996) C8-255-C8-264
Application of Internal Friction to Analysis of Plastic Behaviour of CrystalsA.B. Lebedev
Solid State Physics Division, A.F. Ioffe Physico-Technical Institute, Russian Academy of Sciences, Polytekhnichskaya 26, St. Petersburg 194021, Russia
A relationship between dislocation internal friction, microplastic and macroplastic behaviour of crystals has been considered. Main attention has been paid to the shape of the dislocation hysteresis responsible for the amplitude-dependent internal friction (ADIF) and to a comparison between the macroyield stress σc and microyield stress σe evaluated from the ADIF. It is shown that the same functional form of the ADIF curve may be due to different types of the dislocation hysteresis loop. A proportionality (similarity law) between the temperature dependences σc(T) and σe(T) has been demonstrated. Deviations from the similarity law can be used for analysis of the low and high temperature anomalies of σc(T). The thermal vibrations of atoms rather than the thermal fluctuations are concluded to be responsible for the yield stress temperature dependence.
© EDP Sciences 1996