Influence of rolling strain path on plastic anisotropy in Nb–10Hf–1Ti refractory alloy sheets: Experimental investigation and VPSC modeling

The present work investigates the influence of rolling strain path on the plastic anisotropy of Nb–10Hf–1Ti refractory alloy sheets using experimental characterization and viscoplastic self-consistent (VPSC) simulations. Sheets processed by unidirectional rolling (UR) and two-step cross rolling (CR) were annealed under optimized conditions to achieve the optimum strength–ductility combination. Tensile testing along 0°, 45°, and 90° to the rolling direction revealed pronounced ductility anisotropy in the UR condition, whereas the CR condition exhibited significantly reduced anisotropy. EBSD analysis showed that the reduced anisotropy in the CR sheet originated from the development of a fully recrystallized equiaxed grain structure during annealing. Both UR and CR sheets exhibited strength anisotropy due to crystallographic texture. VPSC modeling revealed that the increase in strength from 0° to 90° loading resulted from a progressive shift in the dominant slip activity from { 110 } ⟨ 111 ⟩ to increased activation of the { 123 } ⟨ 111 ⟩ and { 112 } ⟨ 111 ⟩ slip systems. These results demonstrate that tailoring the rolling strain path effectively mitigates ductility anisotropy while preserving strength anisotropy in Nb–10Hf–1Ti refractory alloy sheets.