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-beta local loading forming was investigated. It is found that four different microstructures can be produced under near-beta local loading forming with the variation of deformation degree and thermal processing path: (primary alpha phases + clustered lamellar alpha phases + transformed beta matrix) produced by small deformation; (primary alpha phases + disordered lamellar alpha phases + aggregated transformed beta matrix) produced by large deformation in the first-loading step; (primary alpha phases + partly globularized second alpha phases + transformed beta matrix) produced by moderate deformation in the second-loading step; (primary alpha phases + fully globularized second alpha phases + aggregated transformed beta matrix) produced by large deformation in the second-loading step. With the increase of strain, the volume fraction of primary alpha 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. (C) 2010 Elsevier B.V. All rights reserved.