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

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 (c) 1015 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.