Effect of deformation inhomogeneity on the microstructure and mechanical properties of large-scale rib–web component of titanium alloy under local loading forming

In the present paper, the effect of deformation inhomogeneity on the microstructure and mechanical properties of large-scale rib–web component of TA15 titanium alloy under near-β local loading forming was investigated. It is found that four different microstructures can be produced under near-β local loading forming with the variation of deformation degree and thermal processing path: (primary α phases + clustered lamellar α phases + transformed β matrix) produced by small deformation; (primary α phases + disordered lamellar α phases + aggregated transformed β matrix) produced by large deformation in the first-loading step; (primary α phases + partly globularized second α phases + transformed β matrix) produced by moderate deformation in the second-loading step; (primary α phases + fully globularized second α phases + aggregated transformed β matrix) produced by large deformation in the second-loading step. With the increase of strain, the volume fraction of primary α phases increases, while the grain size increases first and then decreases. The comprehensive mechanical properties under local loading are close to that under integral loading.