ISSN:
1573-4803
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Maschinenbau
Notizen:
Abstract Single crystals of TiO2 grown by a floating-zone method have been compressed in two directions, [1 0 0] and [0 0 1], at temperatures between 300 and 1300°C in an argon atmosphere. They deformed by {10¯1 〈1 01 〉 slips, except [1 0 0] specimens tested below 600° C, where twinning preceded the slip deformation. Above 800° C, an oxygen reduction occurred during compression tests and the flow stress data were not reproducible. Below 700° C the data were reproducible and the resolved yield stress increased steeply with decreasing temperature. From the temperature and strain-rate dependences, activation analyses have successfully been performed. Activation volume becomes as small as 2b 3 at high stress, and the deformation below 700° C is concluded to be governed by the Peierls mechanism. The total activation enthalpy of deformation by the Peierls mechanism is ∼0.32eV. Applying the string model for the kink-pair formation, the results are consistent if the 〈101〉 dislocation is dissociated into two 1/2〈101〉 partial dislocations. No twinning-anti-twinning asymmetry of slip was observed.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00714049
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