Atomic-scale insight into interaction mechanism between extended dislocation and amorphous phase in high entropy alloys

The crystalline/amorphous dual-phase structure is a new design strategy proposed in recent years to achieve high strength and excellent toughness of high-entropy alloys (HEA). Here, molecular dynamics simulation is used to investigate the effect of amorphous nanopillar size, amorphous nanopillar spacing and temperature on the behavior of extended dislocation overcoming amorphous obstacle in the HEAs. The results indicate that the introduction of amorphous nanopillar can improve the strength the HEA, and the larger the amorphous nanopillar size, the more obvious the strengthening effect. It is worth noting that two stress peaks of the stress-strain curve of the HEA containing amorphous nanopillar correspond to the maximum shear stress required for the leading and trailing dislocations to break away from amorphous nanopillar pinning, while the two peaks of the HEA without amorphous nanopillar represent the shear stress required to drive the leading and trailing dislocations to reach the maximum velocity.