Effect of interfacial structural phase transitions on the coupled motion of grain boundaries: A molecular dynamics study

In this work, the coupled motion of two different phases of Sigma 5(210)[001] grain boundaries was investigated by molecular dynamics simulations of fcc Cu. The effect of interfacial structural phase transitions is shown to have a profound effect on both the shear strength and the nature of the coupled motion. Specifically, the motion of the two different phases is described by ideal coupling factors beta(< 100 >) and beta(< 110 >) that have different magnitudes and even signs. Additionally, the shear strength for the two interfacial phases is observed to differ by up to 40% at the lowest temperatures simulated. The study demonstrates that grain boundary phases transitions may have strong effects on the kinetics of microstructural evolution. (C) 2014 AIP Publishing LLC.