Citation
Esteban Manzanares, Gustavo and Ma, Anxin and Papadimitriou, Ioannis and Martínez Sáez, Enrique and Llorca Martinez, Francisco Javier
(2019).
Basal Dislocation/Precipitate Interactions in Mg-Al Alloys: an Atomistic Investigation.
"Modelling and Simulation in Materials Science and Engineering", v. 27
(n. 7);
pp..
ISSN 1361-651X.
https://doi.org/10.1088/1361-651X/ab2de0.
Abstract
The interaction between edge basal dislocations and β-Mg17Al12 precipitates
was studied using atomistic simulations. A strategy was developed to insert a
lozenge-shaped Mg17Al12 precipitate with Burgers orientation relationship
within the Mg matrix in an atomistic model ensuring that the matrix/precipitate
interfaces were close to minimum energy configurations. It was found that the
dislocation bypassed the precipitate by the formation of an Orowan loop that
entered the precipitate. Within the precipitate, the dislocation was not able to
progress further until more dislocations overcome the precipitate and push the
initial loop to shear the precipitate along the (110) plane, parallel to the basal
plane of Mg. This process was eventually repeated as more dislocations overcome
the precipitate and this mechanism of dislocation/precipitate interaction
was in agreement with experimental observations. Moreover, the initial resolved
shear stress to bypass the precipitate was in agreement with the predictions of
the Bacon–Kocks–Scattergood model.