超细Cr_3C_2粉末的制备

将CrO3溶解于有机溶液中,通过喷雾干燥制得非晶态含铬的粉末前驱体,将前驱体粉末真空还原/碳化后得到超细Cr3C2粉末。采用X射线衍射仪﹑扫描电镜对工艺过程进行分析,分析结果表明:前驱体为10μm～20μm非晶态球形粉末,在真空中当温度升高到400℃时,前驱体粉末开始分解,生成微晶Cr2O3。当温度升高到550℃时,微晶Cr2O3迅速长大,前驱体粉末全部转变为Cr2O3与游离C原子级别混合均匀的复合粉末;温度升高到1150℃时得到碳化完全的Cr3C2粉末,粉末的一次颗粒粒度为0.5μm左右。

Preparation of Ultrafine Cr3C2 Powder

As CrO3 dissolves in organic solvent, the amorphous powder precursor which contains chromium is obtained by spray drying, and the ultrafine Cr3C2 powder is prepared through vacuum reduction or carbonization of the precursor powder. The technological process is investigated and analyzed using X-ray diffractometer, scanning electron microscope (SEM). The results show that the precursor is amorphous spherical powder of (10～20)μm. When the temperature increases to 400℃ in vacuum, the precursor begins decomposition and get crystallite Cr2O3; when the temperature rises to 550℃, the size of the crystallite Cr2O3 increases quickly, all the precursor powder is transformed into the composite powder in which Cr2O3 mixes with free carbon homogeneously atom-level; Cr2O3 is reduced and carbonized by free carbon with the temperature, when the temperature goes up to 1150℃,the totally carbonized Cr3C2 powder was obtained, the first particle size of the powder was about 0.5μm?