Significant reduction in friction and wear of a high-entropy alloy via the formation of self-organized nanolayered structure

Sliding wear-induced nanolayering and its positive impact on wear resistance have been observed in conventional binary alloys with a matrix of high stacking fault energy (SFE),but this concept has never been reported in high-entropy alloys (HEAs) with low SFE.Here,we design and fabricate a (CoCrFeNi)AgHEA,consisting of a face-center-cubic (fcc) CoCrFeNi HEA matrix with low SFE and uniformly dispersed Ag precipitates.In comparison with CoCrFeNi,a significant reduction in friction and wear was found in (CoCrFeNi)AgHEA through the spontaneous formation of nanolayered subsurface microstructure during wear.The finding suggests a novel approach for designing HEAs that can achieve low friction and wear.