硅灰为原料制备类球形亚微米碳化硅粉体

Preparation of Sphere-like Submicron SiC Powder by Using Silica Fume as Raw Material

以硅灰为硅源、葡萄糖为碳源制备粉体先驱体,然后经过炭化和煅烧,制备类球形亚微米碳化硅粉体。实验采用1200、1300、1400、1500℃4种温度煅烧样品,并对产物进行物相、粒度、形貌分析。结果表明:1200℃时,碳热还原反应未发生,硅灰中无定形的二氧化硅转变为结晶形态;剩余三种温度下得到的产物均是3C型碳化硅,在1400℃下能够制备出球形度良好的亚微米碳化硅粉体,其平均粒径约为0.2μm;随着煅烧温度的升高,碳化硅的结晶度增强、粒度变大、球形度变差。

A spherical submicron silicon carbide powder was prepared by carbonizing and calcining the precursor powder fabricated by using the silica fume as silicon source and the glucose as carbon source. The samples were calcined at 1200 ℃, 1300 ℃, 1400 ℃, 1500 ℃, four different temperatures and the phase, particle size and morphology of the products were analyzed. The results show that at 1200 ℃, the amorphous silicon dioxide in silica fume was transformed into crystalline form and the carbothermal reduction reaction did not occur. The products obtained at the remaining three temperatures were 3 C-SiC. A submicron silicon carbide powder with good sphericity and a mean paricle size of about 0.2 μm can be prepared at 1400 ℃. With the increase of calcination temperature, the crystallinity of silicon carbide increases, the particle size becomes larger, and the sphericity becomes worse.