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

We examine the effect of 10 vol.% TiB whisker reinforcement on transformati on superplasticity of Ti-6Al-4V, induced by thermal cycling about the alp p hase transformation range of the matrix under a uniaxial tensile stress. Du ring superplastic deformation, the whiskers gradually align along the exter nal loading axis, as measured by electron back-scattering diffraction of de formed specimens. The composites exhibit a gradual decrease in effective de formation 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. (C) 2001 El sevier Science Ltd. All rights reserved.