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

JY Li and XC Qiu and SN Kong and Z Zhang, PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS, 260, 2300246 (2023).

DOI: 10.1002/pssb.202300246

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 beta 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 368.7MPa. This phenomenon is mainly affected by the interaction length between dislocation and beta 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.

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