Interactions between basal < a > dislocation and 11(2) over bar 2 twin boundary in HCP metal: A molecular dynamics study

SL Hu and HH Chen and Z Zhang, MATERIALS TODAY COMMUNICATIONS, 41, 110193 (2024).

DOI: 10.1016/j.mtcomm.2024.110193

For hexagonal close-packed (HCP) metals having a c/a < root 3 , basal slip is the most common slip system, and 11(2) over bar2 twinning is one of the primary plastic deformation modes when compressive stress is applied along the c-axis. In this work, molecular dynamics simulations have been applied to reveal the interaction mechanism between different basal dislocations and 11(2) over bar2 twin boundaries (TBs) in Mg, Zr and alpha-Ti. When the (0001) 131120 dislocation interacts with the 11(2) over bar2 TB, it is transmuted into a 11(2) over bar2-11(2) over bar1 double twin (DT). With increasing shear stress, the growth of the 11(2) over bar2-11(2) over bar1 DT is impeded by the other side of the 11(2) over bar2 TB, it transmutes into (0001)1/3<1010> dislocations and twin dislocations (TDs). Furthermore, the 11(2) over bar1 TB is capable of transforming into a 11(2) over bar2 TB and a new co-zone 11(2) over bar1 TB, which then forms a twin-twin junction (TTJ) to release stress concentration. When the (0001)1/32110 dislocation interacts with 11(2) over bar2 TBs, it transmuted into a I2 SFs in the twin and a TD with one-layer height on the 11(2) over bar2 TB. But the (0001)1312(1) over bar0 dislocation would be impeded by the 11(2) over bar2 TB and couldn't be transmuted further.

Return to Publications page