(上海交通大学 金属基复合材料国家重点实验室, 上海 200030)
摘 要: 利用钛与B2O3、 B4C和稀土钇之间的化学反应， 采用真空非自耗电弧炉熔炼工艺， 原位合成多元、 多尺度、 不同形状增强体增强的钛基复合材料——(TiB+TiC+Y2O3)/Ti。 利用热力学机理分析了制备该种材料的可行性， 通过X射线衍射仪、 光学显微镜、 扫描电镜、 电子探针和透射电镜分析了复合材料的物相组成、 增强体的微观形貌和材料的显微组织。 结果表明： 复合材料的增强体为TiB、 TiC和Y2O3； 生成的增强体分布均匀； 复合材料的晶粒非常细小； TiB为针状； TiC为等轴状和近似等轴状； Y2O3的形貌随着稀土Y含量的增加从近似等轴状粗化生长为树枝状； 材料中存在较多纳米级的球状增强体； 增强体TiB、 TiC、 Y2O3和钛基体界面干净， 没有界面反应物存在。
关键字: 原位合成； 钛基复合材料； 多元增强体； 氧化钇； 显微组织
（State Key Laboratory of Metal Matrix Composites,
Shanghai Jiaotong University, Shanghai 200030, China）
Abstract: The novel titanium matrix composites, (TiB+TiC+Y2O3)/Ti, which were reinforced with multiple ceramic particulates in different sizes and shapes, were synthesized by the chemical reaction among Ti, B2O3, B4C and rare earth metal Y by vacuum non-consumable arc-melting technique. The thermodynamical feasibility of the in-situ reactions has been analyzed. X-ray diffraction (XRD) was used to identify the phases in the composites. Microstructures of the composites were observed by means of optical microscope (OM), scanning electron microscope (SEM), electron probe and transmission electron microscope (TEM). The results show that the composites consist of Ti, TiB, TiC and Y2O3. The reinforcements are distributed uniformly in the matrix. The crystal grain of the composites is finer than that of pure titanium. TiB grows in needle shapes and TiC grows in equiaxed and near-equiaxed shapes. Y2O3 grows from near-equiaxed shapes to dendritic shapes with increasing the content of Y. Some sphere-shaped reinforcements with nanometer sizes exist in the composites. The interfaces between reinforcements of TiB, TiC and Y2O3 and Ti matrix are clear without any interfacial reactions.
Key words: in-situ synthesis; titanium matrix composite; multiple ceramic particulate reinforcements; Y2O3; microstructure
