In Situ TEM Observation and MD Simulation of Frank Partial Dislocation Climbing in Al–Cu Alloy

抄録

In situ electron irradiation using high-resolution transmission electron microscopy (HRTEM) was performed to visualize the Frank loop evolution in aluminum–copper (Al–Cu) alloy with an atomic-scale spatial resolution of 0.12 nm. The in situ HRTEM observation along the [110] direction of the FCC-Al lattice, Frank partial dislocation bounding an intrinsic stacking fault exhibited an asymmetrical climb along the 〈112〉 direction opposed to those in the reference pure Al under an electron irradiation, with a corresponding displacement-per-atom rate of 0.055–0.120 dpa/s in a high vacuum (1.2 × 10⁻⁵ Pa). We performed theoretical calculations to simulate the asymmetrical climb of the dislocation with Burgers vector b of 1/3〈111〉. The Cu–Cu bonding in Guinier–Preston zones was described as a possible pinning site of the dislocation climb by molecular dynamics simulation.