ULTRASONIC STUDY OF CREEP IN POLYCRYSTALLINE MATERIALS
Creep of the Young's modulus and the internal friction of some polycrystalline rocks and piezoceramic materials were studied. The uniaxial static compressive load was applied instantaneously and then was kept constant for a long time (0…107 s). The loading stress was applied within the range 0…120 MPa. The measurements were performed by means of the ultrasonic method of the loaded complex oscillator. The basic relations of the method were considered. Measurements of creep of some polycrystalline rocks (khibinite and dolomite) and of some piezoceramic materials (TBC-3 and PZT-19) were performed. The advantages of this method over traditional (static) methods for studying the physical mechanisms responsible for creep are shown. These mechanisms are different either for rocks or for piezoceramics, though they are described by the same laws. The measurements were made within the temperature range 20…100 С. This gave the possibility to ascertain the range of activation energies of the corresponding physical processes that take place during compression.
Authors: V. M. Tsaplev, R. S. Konovalov
Direction: Instrument Engineering and Information Technology
Keywords: Polycrystalline rocks, piezoceramics, nonlinear elasticity, internal friction, creep, ultrasonic control, static stress, ultrasonic method, loaded complex oscillator
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