Unusual F 3 stacking fault in magnesium

An unusual F 3 basal stacking fault resulting from twin-dislocation interaction in magnesium is observed in molecular dynamics simulation. The F 3 fault is produced in the twin lattice from the interaction between a migrating ( 10 1 over bar 2 ) twin boundary and a partial dislocation of either a prismatic ( c ) edge, or a prismatic ( c + a ) mixed dislocation in the matrix. The condition is that the partial dislocation needs to have a negative sign and lie on a plane intersecting a compression site of the twin boundary. The F 3 fault can also be generated when a positive basal ( a ) mixed dislocation in the twin lattice, with slip plane intersecting a compression site of the twin boundary, interacts with a basal-prismatic twinning disconnection. The F 3 fault comprises two I 1 faults that have the same character but are separated by two basal layers. It has one end connected to the twin boundary, and the other end bounded by a lattice defect with a Burgers vector identical to that of a 30 degrees Shockley partial dislocation. The formation frequency of the F 3 fault is higher at a lower shear stress (below <^>400 MPa) and/or a lower temperature (100 K and 200 K). The F 3 fault can decompose into a glissile 30 degrees Shockley and a T 2 fault at a temperature above <^>400 K. The relationships between the F 3 fault and other types of basal stacking faults such as I 2 , T 2 or paired I 1 faults that are separated by multiple basal layers are discussed.(c) 2023 Chongqing University. Publishing services provided by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.This is an open access article under the CC BY-NC-ND license ( http://creativecommons.org/licenses/by-nc-nd/4.0/ ) Peer review under responsibility of Chongqing University

Automated summary

An unusual F3 basal stacking fault resulting from twin-dislocation interaction in magnesium is observed in molecular dynamics simulation. The F3 fault is produced in the twin lattice from the interaction between a migrating twin boundary and a partial dislocation in the matrix. The formation frequency of the F3 fault is higher at lower shear stress and/or lower temperature, and it can decompose into other types of stacking faults at higher temperature.