保温时间对SiC-TiC复合粉末物相组成和显微结构的影响

Effect of holding time on phase composition and microstructure of SiC-TiC composite powder

以硅溶胶、淀粉和TiO_(2)为初始原料,采用碳热还原法于1550℃保温不同时间制备了SiC-TiC复合粉末。采用XRD、SEM、EDS探讨了保温时间(1、2和3 h)对合成粉末的物相组成和显微结构的影响。结果表明:所合成的SiC-TiC复合粉末在1550℃保温2 h后合成反应已进行较为完全,合成粉末中除了生成一定量的片状颗粒和大量近似球状颗粒(粒径约在50~100 nm)外,还存在一定量的大小均匀且细长的直径约为50~100 nm的以SiC为主的晶须。

SiC-TiC composite powders were prepared at 1550℃for different durations by the carbothermic reduction method,using silica sol,starch and TiO_(2) as the starting materials.The influences of the holding time(1 h,2 h and 3 h)on the phase composition and the microstructure of the synthesized powders were discussed by XRD,SEM and EDS.The results show that the synthesis reaction of the SiC-TiC composite powder at 1550℃for 2 h is relatively complete.In addition to a certain amount of flake particles and many approximately spherical particles(with particle diameter of 50-100 nm),some SiC-based whiskers with uniform sizes and the diameter of 50-100 nm exist.