Searching for evidence of strengthening by short-range order in the CrCoNi medium entropy alloy

Abstract: The coupling of strength to short-range order (SRO) in the CrCoNi medium entropy alloy remains hotly debated, with conflicting reports supporting and opposing SRO-induced strengthening continuing to emerge. A direct understanding of this effect remains elusive, due to difficulties in the quantification of SRO. Here, we deliver a structurally agnostic analysis that searches for unusual patterns in crystal size effects as evidence of SRO-induced strengthening. For this purpose, we assemble a large dataset of strengthening measurements drawn from a range of thermomechanical processing conditions known to produce SRO. Based on a comparative analysis with pure metal benchmarks, we find no evidence for significant coupling of SRO to strengthening in CrCoNi, and that patterns interpreted as a positive finding are likely explained by cross-study measurement scatter. Nevertheless, we leverage our analysis to provide an upper bound estimate of SRO-induced strengthening in the unlikely scenario where other sources of scatter are negligible.