| Numéro |
J. Phys. IV France
Volume 10, Numéro PR6, April 2000
The Sixth Japan-France Materials Science SeminarJFMSS-6 Microstructural Design for Improved Mechanical Behaviour of Advanced Materials |
|
|---|---|---|
| Page(s) | Pr6-165 - Pr6-169 | |
| DOI | https://doi.org/10.1051/jp4:2000629 | |
JFMSS-6
Microstructural Design for Improved Mechanical Behaviour of Advanced Materials
J. Phys. IV France 10 (2000) Pr6-165-Pr6-169
DOI: 10.1051/jp4:2000629
Intragranular plasticity of β Si3N4 between 20 °C and 700 °C
X. Milhet1, J.L. Demenet1 and J. Rabier11 Laboratoire de Métallurgie Physique, UMR 6630 du CNRS, Université de Poitiers, UFR Sciences, SP2M1, avenue Marie et Pierre Curie, BP. 30179, 86962 Futuroscope Chasseneuil cedex, France
Abstract
Intragranular plasticity induced by indentation is studied in β Silicon Nitride between room temperature and 700°C by Transmission Electron Microscopy (TEM). It is shown that all the dislocations resulting unambiguously from plastic deformation have a Burgers vector b = [0001] and a dominant screw character. This can account for a large Peierls stress along the [0001] direction and a larger mobility of edge dislocation segments as compared to screw ones. Dislocations bowing out of screw direction are found to glide in {10-10} prismatic planes. Cross-slip is evidenced from the dislocation microstructure observations. It is found to occur between {10-10} prismatic planes at 20°C whereas {11-20} is found to be a new deviation plane at 700°C. Those observations are discussed in relation with the possible core structure of [0001] screw dislocations.
© EDP Sciences 2000