Katzarov, I.H.; Drenchev, L.B. Unveiling the Mechanisms of High-Temperature 1/2[111] Screw Dislocation Glide in Iron–Carbon Alloys. Crystals2022, 12, 518.
Katzarov, I.H.; Drenchev, L.B. Unveiling the Mechanisms of High-Temperature 1/2[111] Screw Dislocation Glide in Iron–Carbon Alloys. Crystals 2022, 12, 518.
Abstract
We have developed a self-consistent model for predicting
velocity of 1/2[111] screw dislocation in binary iron--carbon alloys gliding by a high-temperature Peierls mechanism.
The methodology of modelling includes: (i) Kinetic Monte-Carlo (kMC) simulation of carbon segregation in dislocation core and determination the total carbon occupancy of the core binding sites;
(ii) Determination of kink-pair formation enthalpy of
a screw dislocation in iron---carbon alloy;
(iii) KMC simulation of carbon drag and determination of
maximal dislocation velocity at which the atmosphere
of carbon atoms can follow a moving screw dislocation;
(iv) Self consistent calculation of average velocity of
screw dislocation in binary iron--carbon alloys gliding by a
high-temperature kink-pair mechanism under constant strain rate.
We conduct a quantitative analysis of the conditions of stress and temperature at which screw dislocation glide in iron--carbon alloy is accomplished by a high-temperature kink-pair mechanism.
We estimate the dislocation's velocity at which
screw dislocation brakes away from the carbon cloud
and thermally-activated smooth dislocation propagation is interrupted by sporadic bursts controlled by athermal dislocation activity.
Copyright:
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