Superplastic-like flow in a fine-grained equiatomic CoCrFeMnNi high-entropy alloy

A CoCrFeMnNi high-entropy alloy (HEA) showed elongation to failure similar to 320% at T = 1023 K and a strain rate. epsilon = 10(-4) s(-1). Strain hardening and texture weakening occurred at low. e, whereas flow softening and texture strengthening were observed at high. epsilon (> 3 x 10(-2) s(-1)) experiments. The strain rate sensitivity (m) decreased from 0.5 to similar to 0.25 with increasing. epsilon. Deformation with m similar to 0.5 and deformation-enhanced grain growth at low. e indicated superplasticity associated with grain boundary sliding. The grain boundary diffusion coefficient diminished by a factor of similar to 4 in the HEA. Concurrent nucleation, growth and cavity interlinkage caused premature failure compared with conventional superplastic alloys. [GRAPHICS] IMPACT STATEMENT FCC CoCrFeMnNi HEA shows superplastic-like flow with similar to 320% elongation at 1023 K and 10(-4) s(-1) strain rate originating from grain boundary sliding.