真空原位合成SiC-TiC复合粉末及其氧化性能研究

STUDY ON SIC-TIC COMPOSITE FINE POWDER MIXED BY VACUUM ORIGINAL POSITION AND ITS OXIDATION SUSCEPTIBILITY

以碳化硅、二氧化钛和炭黑为原料,在真空条件下原位合成SiC-TiC复合粉末。采用XRD、SEM等测试手段对合成SiC-TiC复合粉末的物相组成和显微形貌进行表征,同时对合成的粉末样品的氧化性能进行探讨。实验结果表明:在本实验条件下,SiC-TiC复合粉末适宜的合成条件为在1350℃保温1h。在SiC粉末中原位生成的TiC,以粒径为0.1～0.2μm左右的小颗粒存在。SiC-TiC复合粉末在氧化过程中,在较低温度下TiC优先氧化生成TiO2,在较高温度下(1100℃左右)SiC才开始氧化生成SiO2。

SiC-TiC composite powders were synthesized in vacuum by in-situ reaction between SiC, TiO2 and carbon black. The phase composition and morphology of SiC-TiC composite powders were investigated by X-ray diffraction and scanning electron microscope. The antioxidation performance of SiC-TiC composite powders was also discussed. The results show that the suitable condition for synthesizing SiC-TiC composite powders is at 1350℃ for lh. The size of in-situ created TiC particles in SiC powders is about 0.1 - 0.2μm. In the oxidation process, TiC reacts in priority with O2 to form TiO2 at relatively low temperatures, then SiC reacts with O2 to form SiO2 at about 1100℃ .