Load partition and microstructural evolution during hot deformation of Ti-6Al-6V-2Sn matrix composites, and possible strengthening mechanisms

A Ti-6Al-6V-2Sn alloy reinforced with two different volume fractions of TiC particles was subjected to tensile deformation at 750 °C during in-situ high energy synchrotron diffraction to study the load partition between the α-, β-, and TiC phases. Elastic anisotropies and stress differences are shown for the different phases. Possible strengthening mechanisms are analysed and quantified to explain the differences observed in the peak stresses between the matrix and the composites. TiC particles, with an inhomogeneous distribution within the matrix, are capable of bearing load. Although this can be considered as the main strengthening mechanism, it has negligible effect up to the peak stress of the matrix. The evolution of the microstructure during the hot deformation is also analysed and related to the load partition and the damage of the composite.