Local lattice distortion in NiCoCr, FeCoNiCr and FeCoNiCrMn concentrated alloys investigated by synchrotron X-ray diffraction

Highlights: • Fine-grained fcc concentrated alloys with weak texture were prepared for lattice distortion characterization. • Lattice distortion in NiCoCr, FeCoNiCr and FeCoNiCrMn concentrated alloys is quantitatively characterized for the first time. • Lattice distortion in NiCoCr (0.23%) and FeCoNiCrMn (0.24%) is comparable, while negligible in FeCoNiCr (0.04%). • Size mismatch is not the sole factor to induce lattice distortion in high-entropy alloys. Severe lattice distortion is presumptively considered as a core effect of high-entropy alloys, but quantitative measurements are still missing. Here, we demonstrate that the lattice distortion in high-entropy alloys can be quantitatively analyzed based on pair distribution function obtained from synchrotron X-ray diffraction. By applying this method to equiatomic NiCoCr, FeCoNiCr and FeCoNiCrMn concentrated alloys, we found that the local lattice distortion in the NiCoCr (0.23%) and FeCoNiCrMn (0.24%) alloys are comparable while negligible in the FeCoNiCr alloy (0.04%). The origin of local lattice distortion in the NiCoCr and FeCoNiCrMn concentrated alloys was discussed.