Effects of Applied Strain on Interface Microstructure and Interdiffusion in the Diffusion Couples

Abstract

The effects of applied strain on the interface microstructure and atomic interdiffusion in the binary alloy diffusion couples were studied using the phase-field model. In the two-phase diffusion couples, the single-phase regions are formed beside the interface without applied strain, and the width of single-phase regions enlarges as temperature increases. When the strain is applied, the phases are elongated and they are across the initial interface, which makes the diffusion couples to syncretize as the temperature increases or concentration difference decreases. In the diffusion couples formed by single and two phases, the larger composition difference results in the larger movement distance of interface, the atomic diffusion direction is determined by the initial composition difference. Under the applied strain, the elongated two phases are also across the initial interface with the small concentration difference. However, when the concentration difference is large, the two-phase region is recessional as the single-phase region moves forward. When the applied strain makes the morphology parallel to the initial interface of the diffusion couple, the single-phase regions are formed beside the interface.