Abstract： High-performance ultrafine SiC powders were prepared by the method of ball milling taking low grade coarse SiC powders as raw materials. Effect of ball milling parameters such as milling time, mass ratio of ball to powders and rotation velocity on the microstructure and properties of SiC powders was researched. The results show that particle size and vibration compaction density of the SiC powders decrease with the increase of milling time, mass ratio of ball to powders and rotation velocity. However, taper height of the SiC powders increases, namely flowability of the SiC powders becomes poor. X ray diffraction peaks intensity decreases and full-widths at the half maximum (FWHM) of SiC diffraction peaks obviously broadens, which illustrates that grain sizes of the SiC powders are refined by ball milling. The optimal ball milling parameters are as follows. The rotation velocity is 200 r/min, the mass ratio of ball to powders is 10 and the milling time is 40 h.

Keywords: ball milling; SiC powder; microstructure