Molecular Dynamics Simulation of Interaction between Edge Dislocations and Stable β‐Phase Precipitates in Aluminum Alloy

Abstract

Stable precipitate takes the essential role for material strengthening in Al–Mg–Si alloys. To reveal how the stable precipitate works in material strengthening, a molecular dynamics model is carried out to show the interaction between the edge dislocations and the plate‐shaped β phase of Mg2Si. The critical resolved shear stress (CRSS) is related to the precipitate characteristics including sizes and thickness directions. The CRSS increases with the increase of the precipitate size. When the thickness direction of precipitate changes from [001] to [100], the CRSS increases from 326.76 to 368.7 MPa. This phenomenon is mainly affected by the interaction length between dislocation and β phase. With the increase of interaction length, the interaction time for dislocation to overcome pinning increases. The critical bending angle of dislocation can be affected by the interaction time and shear strain rate. The relationship between the critical bending angle and the CRSS in Al–Mg–Si alloy is then established.