Construction of a new n-body potential and multi-scale investigations of the direct alloying behaviors for immiscible W/Cu system

Abstract

Achieving direct alloying at the tungsten/copper (W/Cu) interface is crucial for the fabrication of laminar metal matrix composite (LMMC) plasma-facing components (PFCs) of fusion reactors based on immiscible W/Cu systems. Our previous work has accomplished direct alloying between immiscible W and Cu, forming a diffusion layer with a thickness of approximately 22–32 nm at the interface. The performance of the interface directly affects the lifetime and reliability of W/Cu LMMC. Multi-scale calculations are designed since some interface properties cannot be directly measured or observed experimentally in real-time and in situ. Firstly, a new potential is constructed to overcome the limitations that the existing W/Cu potential cannot accurately describe the W/Cu alloying process. Secondly, molecular dynamics (MD) simulations use the new potential to study interfacial properties and calculate the diffusion depth at the W/Cu interface. Lastly, combining MD, FEM, and image visualization techniques, a multi-scale method of the crack propagation rate at the W/Cu interface is used to predict the thermal fatigue life of W/Cu LMMC PFCs prepared by nano-active structure-induced alloying. Our simulation results agree with experimental values and literature results, demonstrating the reliability of the new W/Cu potential and the accuracy of our designed multi-scale method. Directly alloyed W/Cu LMMCs have the potential to be utilized in fusion reactors.