Rapid transformation of hexagonal to cubic silicon carbide (sic) by electric discharge assisted mechanical milling

Silicon carbide powder was successfully transformed from hexagonal SiC into cubic SiC using the electric discharge assisted mechanical milling (EDAMM) method. The milling process was conducted in nitrogen plasma at atmospheric pressure. The effects of pulsed alternating current (AC) and direct current (DC) discharge on product formation were investigated. Products were characterized by X-ray diffractometry, scanning electron microscopy, transmission electron microscopy and nanohardness. It was found that hexagonal SiC can be transformed into cubic SiC under EDAMM processing, near complete transformation occurring within 5 min when applying AC mode electrical pulses, and within 10 min when applying DC mode discharges.