Elastic-plastic behavior of nickel-based single crystal superalloys with γ-γ′ phases based on molecular dynamics simulations

JZ Cao and YG Zhang and ZK Zhang and JP Fan and Q Dong and YY Fang, CHINESE PHYSICS B, 34, 046204 (2025).

DOI: 10.1088/1674-1056/adb40f

The effects of temperature and Re content on the mechanical properties, dislocation morphology, and deformation mechanism of gamma-gamma ' phases nickel-based single crystal superalloys are investigated by using the molecular dynamics method through the model of gamma-gamma ' phases containing hole defect. The addition of Re makes the dislocation distribution tend towards the gamma phase. The higher the Re content, the earlier the gamma phase yields, while the gamma ' phase yields later. Dislocation bends under the combined action of the applied force and the resistance of the Re atoms to form a bend point. The Re atoms are located at the bend points and strengthen the alloy by fixing the dislocation and preventing it from cutting the gamma ' phase. Dislocations nucleate first in the gamma phase, causing the gamma phase to deform plastically before the gamma ' phase. As the strain increases, the dislocation length first remains unchanged, then increases rapidly, and finally fluctuates and changes. The dislocation lengths in the gamma phase are larger than those in the gamma ' phase at different temperatures. The dislocation length shows a decreasing tendency with the increase of the temperature. Temperature can affect movement of the dislocation, and superalloys have different plastic deformation mechanisms at low, medium and high temperatures.

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