Effects of direct rolling deformation on the microstructure and tensile properties of the 2.5 vol% (TiBw+TiCp)/Ti composites

In this paper, as cast 2.5 vol% (TiBw+TiCp)/Ti composites were subjected to direct rolling down to 45%, 65% and 85% reduction in thickness in the (alpha+beta) phase region. The microstructure evolution and tensile properties of the composites during direct rolling were investigated. The results show that increasing of the rolling deformation contributes to the refinement of primary a phase (alpha(p)) and the improvement of the distribution uniformity of TiBw and TiCp. Furthermore, both the tensile strength and elongation are significantly enhanced with increasing of the rolling deformation. As the rolling reduction reaches 85%, the 2.5 vol% (TiBw+TiCp)/Ti composites exhibit an excellent balance of strength and elongation to failure both at RT and 600 degrees C, which is mainly attributed to the microstructure refinement and the load-sharing effect of TiBw and TiCp. Fracture analysis shows that the fracture TiBw and TiCp followed by the ductile failure of the matrix is the failure mechanism of the composites both at RT and 600 degrees C.