Abstract
Six groups of fcc solid/solid diffusion couples, including Ni-Cr-Fe/ low-entropy (pure Ni, and NiCo, NiCr, and NiCoCr) alloys, Ni-Cr-Fe/ medium-entropy (CoCrNi) alloys, and Ni-Cr-Fe/ high-entropy (CoCrFeNi) alloys, were prepared, and their composition profiles were experimentally measured. Concentration-dependent interdiffusion and tracer diffusion coefficients in fcc Ni-Co-Cr-Fe system at 1473 K were retrieved with the aid of High-throughput Determination of Interdiffusion Coefficients (HitDIC) software and their reliability was validated. In most cases, D_(CrCr)~(Ni)> D_(FeFe)~(Ni)> D_(CoCo)~(Ni). The comprehensive comparison between the inter-diffusivities/tracer diffusivities in the NiCo, NiCr, NiCoCr low-entropy, CoCrNi medium-entropy, and CoCrFeNi high-entropy alloys and those reported data available in the literatures indicates that the inter-diffusivities Co, Cr, and Fe in low-entropy alloys are the largest than those in the other two types of alloys. While the tracer diffusivity in Co-Cr-Fe-Ni HEAs may have no sluggish phenomenon when the absolute temperature is used.
NSTL
Elsevier