<p>Effects of weld zone (WZ) and post-weld annealing on deformation behavior of electron-beam-welded Nb–10Hf–1Ti (wt.%) alloy sheets were investigated using uniaxial tensile and shear tests. Columnar dendritic grain structures were identified within WZ with densely distributed fine HfO₂, resulting in ~ 39% higher hardness than base metal (BM). DIC analysis revealed negligible strain in WZ during tensile loading of the welded specimen, leading to fracture in the BM away from the WZ. Post-weld annealing caused dendritic dissolution and precipitate coarsening, homogenizing hardness and enabling the WZ to actively participate in deformation, with fracture at gauge center. In shear tests, the WZ presented the highest load-bearing capacity in the welded specimen, while annealing marginally reduced the peak load by ~ 3.5% than monolithic specimen. Fractographic analysis also evidenced marginal reduction in tensile fracture strain of the weld-annealed specimen, and also the participation of WZ in shear deformation.</p>