Microstructure and properties of titanium and Ti-6Al-4V with and without TiCp reinforcement deformed by transformation superplasticity

Transformation superplasticity, whereby large failure strains are produced by thermally cycling a material about a solid-state phase transformation under the action of an applied stress, was investigated for Ti and Ti-6Al-4V as well as Ti/TiCP and Ti-6Al-4V/TiCP composites. The plastic strain accumulated on each thermal cycle about the transformation range of the matrix is measured as a function of applied stress. The results are discussed in the framework of existing continuum mechanics-based models. Microstructural evolution during superplastic deformation is studied and related to the roam temperature tensile properties of deformed specimens.