Analysis of Data on the Evolution of the Dislocation Structure of Nanostructured Zirconium Obtained by the Low-temperature Acoustic Technique

Analysis of Data on the Evolution of the Dislocation Structure of Nanostructured Zirconium Obtained by the Low-temperature Acoustic Technique

The temperature dependences of acoustic properties of nanostructured and polycrystalline zirconium was investigated in the temperature range 100 – 340 K. The effect of extreme plastic deformation and subsequent annealing on main parameters of the Koiwa-Hasiguti acoustic relaxation in zirconium is studied in detail. It is known that due to intensive plastic deformation the relaxation intensity considerably increases and the temperature and the width of the corresponding relaxation peak systematically decrease with reduction of the mean grain size in the samples. Annealing leads to a partial recovery of the relaxation intensity and the peak temperature back to the initial values in undeformed samples but the width of the relaxation peak indicates an additional decrease. The majority of the effects observed can be explained by changes in dislocation subsystems of the samples during intense plastic deformation and annealing. An effect of a random scatter of the relaxation time on the key parameters of the Koiwa-Hasiguti peak is defined using the statistical analysis based on the lognormal distribution. It is shown, that the parameter β of the lognormal distribution defines the width, height and asymmetry of the peak and also allows estimating the relaxation strength from the peak height. An algorithm of retrieving of the parameter β from experimental data is provided.

Author (s) Details

P. P. Pal-Val
B. Verkin Institute for Low Temperature Physics and Engineering, National Academy of Sciences of Ukraine, Nauki Ave. 47, Kharkov 61101, Ukraine.

A. P. Rybalko
S. Kuznets Kharkov National University of Economics, Nauki Ave. 9a, Kharkov 61166, Ukraine.

L. N. Pal-Val
B. Verkin Institute for Low Temperature Physics and Engineering, National Academy of Sciences of Ukraine, Nauki Ave. 47, Kharkov 61101, Ukraine.

E. N. Vatazhuk
B. Verkin Institute for Low Temperature Physics and Engineering, National Academy of Sciences of Ukraine, Nauki Ave. 47, Kharkov 61101, Ukraine.

View Book :- https://stm.bookpi.org/NUPSR-V1/issue/view/23

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