Direct observation of self-suppressed slip localization in refractory high-entropy alloy

Stable plastic deformability is crucial for the safe service and processing of refractory high-entropy alloys (RHEAs). However, localized planar-slip bands in these RHEAs are generally considered to promote strain localization and impair plasticity. Here, we present evidence for self-suppressed slip localization in Al7Nb34Ti34Zr25 RHEA. An initially localized planar-slip band does not remain continuously dominant, but undergoes repeated branching and activation of neighbouring slip pathways. Self-suppression denotes the interruption, rather than elimination, of persistent localization within the same dominant slip channel. This redistribution of slip activity is associated with strong pinning by chemical-order domains and accumulation of residual dislocation structures. This may locally obstruct repeated glide along the original band and favour participation of alternative pathways.