The temperature dependence of the strength of Ir3Nb with the L12structure has been investigated using compression tests between - 196 and 1200°C. Below room temperature, the strength decreased with increasing temperature. An anomalous temperature dependence of the strength was observed between room temperature and 800° C; the strength increased with increasing temperature. Above 800° C, the strength again decreased with increasing temperature. The Burgers vectors of the dislocations in samples deformed at room temperature, 600°C and 1200°C were investigated using both dark-field weak-beam imaging techniques and the equithickness fringe method with a transmission electron microscope. The a < 110) -type superdislocations dissociated into (a/3) (211)-type super partial dislocations bounding a superlattice intrinsic stacking fault in the samples deformed at 600 and 1200° C. Dissociation of the antiphase boundary bounding dislocation was not observed at any of the deformation temperatures.
ASJC Scopus subject areas
- Condensed Matter Physics