Whisker alignment of Ti–6Al–4V/TiB composites during deformation by transformation superplasticity

We examine the effect of 10 vol.% TiB whisker reinforcement on transformation superplasticity of Ti–6Al–4V, induced by thermal cycling about the α/β phase transformation range of the matrix under a uniaxial tensile stress. During superplastic deformation, the whiskers gradually align along the external loading axis, as measured by electron back-scattering diffraction of deformed specimens. The composites exhibit a gradual decrease in effective deformation rate during superplastic elongation. This effect is attributed to increased load transfer from matrix to whisker upon whisker alignment, and is explained with elastic calculations of stress partitioning.