The Effect of Rolling Temperature on the Microstructure and Mechanical Properties of 5 vol.% (TiBw + TiCp)/Ti Composites

In this study, as-cast 5 vol.% (TiBw + TiCp)/Ti composites underwent multi-step rolling at different phase regions to explore the effect of rolling temperature on the microstructure and mechanical properties of the composite sheets. The matrix microstructures of the composites rolled at 1293 K and 1383 K are, respectively, equiaxed and lamellar microstructures, which are significantly refined compared to that of the as-cast condition. After rolling, the uniformity is improved while the aspect ratio of the reinforcements becomes reduced. Based on the interaction between the matrix and the reinforcements, the microstructure evolution mechanisms of the composites rolled in the (α + β) and β phase regions are clarified. Compared to the as-cast composite, the tensile strength and elongation of the as-rolled composites are markedly improved, both at room and elevated temperatures. The strengthening mechanisms of the as-rolled composites are mainly due to the matrix microstructure refinement and the load-sharing effect of uniformly distributed reinforcements.