Coarse slip bands and non-Schmid’s translational slip lead to shear bands formation in body-centered cubic HfNbTaTiZr high-entropy alloy

The microstructural evolution and shear band formation mechanism in an equiatomic HfNbTaTiZr body-centered cubic (BCC) high-entropy alloy (HEA) were systematically investigated during cold rolling. Microstructural observations revealed the development of coarse, and straight slip bands at early deformation stages. Detailed analysis of slip band-grain boundary (GB) interactions showed evidence of continuous slip transmission across GB regions. With increasing deformation, localized strain regions evolved along the prior slip bands, eventually leading to the formation of well-defined shear bands. Non-Schmid effects were found to promote slip continuity across GBs, preferentially along the {112} slip planes, thereby facilitating strain localization. The present study highlights the critical role of flow localization on {112} planes, non-Schmid deformation behavior, and strain accommodation mechanisms particularly at slip band-GB intersection regions in governing shear band formation in the HfNbTaTiZr BCC-HEA.