Dissociation of Tilt Dislocation Walls in Au

The movement or dissociation of dislocations is significantly important for better understanding the plastic deformation mechanisms and mechanical properties of metals. It is commonly believed that a dislocation < 110 > /2 in Au is easy to dissociate into a pair of Shockley partial dislocations < 112 > /6 due to low stacking fault energy (SFE). Contrary to this prevailing perception, the present atomistic modeling demonstrates that this reaction could be completely suppressed when dislocations < 110 > /2 are grouped into tilt walls, consistent with our experimental observations. Such phenomenon is actually the extreme case accompanying with the variation of Burgers vectors of partials with tilt angle, as revealed by a series of simulations, from which it is clearly seen that the Burgers vectors of partials deviate considerably from that of Shockley partials, enormously depending on the tilt angle. Our findings could facilitate a better understanding on many phenomena and properties of face-centered cubic metals (FCC).

Automated summary

The movement and dissociation of dislocations play a significant role in understanding the plastic deformation mechanisms and mechanical properties of metals. Previous beliefs about the dissociation of dislocations in Au have been proven wrong, as new atomistic modeling and experimental observations show that this reaction can be completely suppressed. The deviation of Burgers vectors of partials from Shockley partials depends heavily on the tilt angle, which has important implications for better understanding face-centered cubic metals (FCC).