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Mechanical Damping Arising from Dislocation Motion in Sapphire and Ruby Crystals
Author(s) -
Pezzotti Giuseppe,
Ota Ken'ichi
Publication year - 1997
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1997.tb03109.x
Subject(s) - dislocation , materials science , sapphire , perpendicular , torsion (gastropod) , crystal (programming language) , creep , condensed matter physics , amplitude , composite material , optics , physics , geometry , medicine , laser , mathematics , surgery , computer science , programming language
Internal friction was measured up to the melting point (i.e., T m ≈ 2050°C) in sapphire and two ruby single crystals (chromium content of 0.1 and 0.5 wt%), as a function of strain amplitude, temperature, and composition. The frequency range of the measurements was 6.7–17 Hz. Static (torsional creep) experiments also were performed up to very high temperatures, to provide further phenomenological insight about the mechanism of crystal deformation. Results of dynamic and static experiments were analyzed and discussed in terms of dislocation motion along the basal (0001) plane, perpendicular to which the torsion axes of the crystals were oriented. Particular emphasis was placed on isolating the role of chromium concentration, in regard to impeding dislocation motion and multiplication. An equivalent spring‐dashpot model, which attempts to represent the damping results quantitatively, also has been given.