Microstructural evolution and mechanical properties of near α-Ti matrix composites reinforced by hybrid (TiB+Y2O3) with bimodal size

In this study, bimodal size (TiB + Y2O3)/near alpha-Ti composites were fabricated by in situ casting route. The uniformly distributed micron TiB and micro-or nano size Y2O3 lead to significant changes in matrix microstructure and compressive properties. With the decreasing of TiB/Y2O3 volume ratios, significant refinement of a colony and gradual improvement of compressive strength can be obtained. As TiB/Y2O3 volume ratio reaches 4:1, the composite displays the optimal ultimate compressive strength and ductility. And the relative strengthening mechanism along with the evolution of the compressive ductility is discussed. (C) 2017 Elsevier Ltd. All rights reserved.