Plastic Creep Features of Sapphire at Near-Melting Point Temperatures
- Authors: Stepantsov E.A.1
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Affiliations:
- Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics,” Russian Academy of Sciences
- Issue: Vol 64, No 6 (2019)
- Pages: 947-951
- Section: Physical Properties of Crystals
- URL: https://journals.rcsi.science/1063-7745/article/view/194337
- DOI: https://doi.org/10.1134/S1063774519050213
- ID: 194337
Cite item
Abstract
The anomalous plastic creep of sapphire crystals in the temperature range of 1890–2050°С, which includes their melting point, has been studied. A method is developed for maintaining crystal in the state of crystal–melt phase transition for a long time, sufficient for carrying out and finishing mechanical tests. Crystal deformation was performed in the creep mode under uniaxial compression along the [10\(\bar {1}\)2] direction. A sharp (stepwise) increase in the creep rate is found when reaching the melting point: it becomes more than an order of magnitude higher as compared with that at near-melting point temperatures. A hypothesis is proposed to explain the found phenomenon by the existence of a transition state between the solid and liquid phases of aluminum oxide, which is characterized by lattice conservation at a sharp increase in the self-diffusion rate.
About the authors
E. A. Stepantsov
Shubnikov Institute of Crystallography, Federal Scientific Research Centre “Crystallography and Photonics,”Russian Academy of Sciences
Author for correspondence.
Email: stepantsov@crys.ras.ru
Russian Federation, Moscow, 119333