In situ synthesis of hybrid-reinforced titanium matrix composites

摘要

Novel hybrid-reinforced (TiB+La_2O_3)/Ti composites were in situ synthesized utilizing the reaction between Ti, LaB_6 and B_2O_3 through homogeneous melting in a non-consumable vacuum arc remelting furnace. The thermodynamics of in situ synthesis reaction were analyzed. The phases in the composites were identified by X-ray diffraction (XRD) and the microstructures of the composites were examined by optical microscope (OM), backscattered scanning electron microscope (SEM) and field-emission SEM. Three kinds of reinforcements were found in the composites: La_2O_3 particles (diameter: ～ 2 μm), TiB whiskers (width: ～ 3 μm) and TiB plates (thickness: ～ 1.5 μm). The reinforcements' sizes were fine and they were homogeneously distributed in the matrix.