Effect of Network Structure Morphology on Fatigue Crack Propagation in Sintered Compact Composed of High‐Entropy Alloy CrMnFeCoNi and 304SS

ABSTRACT In this study, high‐entropy alloy (HEA; CrMnFeCoNi) and austenitic stainless steel (SS; AISI304L) powders were consolidated to fabricate sintered compacts having a network structure composed of a coarse‐grained SS structure surrounded by an interconnected fine‐grained HEA structure. A small‐particle‐size HEA powder and large‐particle‐size SS powder were mixed at various volume ratios and then consolidated by spark plasma sintering. The threshold stress intensity factor range, Δ K th , for the sintered compacts with a HEA network structure did not depend on the volume fractions of HEA and SS, whereas Δ K th for the sintered compacts with the opposite SS network structure tended to decrease with increasing HEA content. The effective threshold stress intensity factor range, Δ K eff,th , for the HEA network structure was higher than that for the opposite SS network series because fatigue cracks preferentially propagated through the coarse‐grained SS structure with a high Δ K eff,th in the HEA network structure.