Yield stress anomaly controlled by the phase stability in NbSi2 single crystals

Effects of alloying elements on the deformation behavior of C40-NbSi2 were examined. Yield stress anomaly (YSA), caused by the formation of a dragging atmosphere around dislocations, was found to be controlled by two factors. Dragging atmospheres were considered to be formed by point defects such as vacancies at 900–1200 °C and by substitutional elements at higher temperatures. Variation in YSA depended on the phase stability at higher temperatures. The magnitude of the YSA could be enhanced by increasing the stability of the C11b-phase in C40-NbSi2.