In-situ neutron diffraction studies on high-temperature deformation behavior in a CoCrFeMnNi high entropy alloy

•We investigated an equiatomic, face-centered-cubic, CoCrFeMnNi high entropy alloy.•We applied in-situ neutron diffraction measurements.•The lattice-strain, diffraction peak-width, and intensity evolutions are studied.•Creep is activated at 1,000 K and the associated diffraction patterns are reported.•TEM results support the factual and descriptive characters of neutron patterns.

An equiatomic, face-centered-cubic, CoCrFeMnNi high-entropy alloy was tensile tested at 800 K and 1,000 K with a nominal strain rate of 6.7 × 10−6 s−1. In addition to the macroscopic (bulk) behavior, mesoscopic (lattice) phenomena during the pseudo-creep deformation were investigated simultaneously using in-situ neutron diffraction. The evolutions of lattice strains, peak widths, and intensities of several hkl reflections suggest that the dominant deformation mode is the dislocation glide at 800 K and diffusion-controlled dislocation creep at 1,000 K.