Modeling of the dislocation dynamics in Ni{sub 3}Al and the flow stress anomaly
- CNRS-ONERA, Chatillon (France)
Ni{sub 3}Al single crystals are known to exhibit a flow stress anomaly between 200 and 800 K. The purpose of this work is to examine such an anomaly by means of a simulation of the dislocation dynamics at a mesoscopic scale. The simulation basic rules are: (i) the dislocation glide in {l_brace}111{r_brace} octahedral planes, (ii) the conditions at which screw lines are locked and unlocked by the formation of Kear-Wilsdorf locks, (iii) the mobility of jogs in the {l_brace}100{r_brace} cube plane. The results suggest that two different temperature regimes occur in the domain of the anomaly. At low temperatures, the plastic flow is governed by kink bow-out, itself a function of the kink length. At high temperatures, the plastic flow is governed by the unlocking of the weakest Kear-Wilsdorf locks in the microstructure. These outcomes of the simulation are discussed in relation with the existing theoretical models of the flow stress anomaly.
- OSTI ID:
- 571853
- Report Number(s):
- CONF-961202--
- Country of Publication:
- United States
- Language:
- English
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