Influence of Al, Cu and Mn additions on diffusion behaviors in CoCrFeNi high-entropy alloys

The interdiffusion coefficients in Al0.2CoCrFeNi, CoCrCu0.2FeNi, and CoCrFeMn0.2Ni high-entropy alloys were efficiently determined by combining diffusion couple experiments and high-throughput determination of interdiffusion coefficients (HitDIC) software at 1273-1373 K. The results show that the addition of Al, Cu, and Mn to CoCrFeNi high-entropy alloys promotes the diffusion of Co, Cr, and Fe atoms. The comparison of tracer diffusion coefficients indicates that there is no sluggish diffusion in tracer diffusion on the thermodynamic temperature scale for the present Al0.2CoCrFeNi, CoCrCu0.2FeNi, and CoCrFeMn0.2Ni high-entropy alloys. The linear relationship between diffusion entropy and activation energy reveals that the diffusion process of atoms is unaffected by an increase in the number of components as long as the crystal structure remains unchanged.