Effect of Aluminium on High-Energy Ball Milling and Spark Plasma Sintering of Silicon Nitride
A commercial silicon nitride powder with oxide sintering additives was ground with high-energy ball mill to obtain nano-sized powder. Metallic aluminium powder was added as a grinding additive. Effect of high-energy ball milling was evaluated by X-ray diffraction analysis. After milling, height of background increased and peak height of silicon nitride decreased in XRD chart, which suggested that vitrification and/or decrease in grain size of silicon nitride occurred. The milled powders were sintered by spark plasma sintering system. Aluminium nitride was formed during sintering by reaction of aluminium and atmospheric nitrogen. Dense nano-ceramics, which were composed of silicon nitride and sialon, were obtained by sintering at 1550 oC.
Hai-Doo Kim, Hua-Tay Lin and Michael J. Hoffmann
T. Nishimura et al., "Effect of Aluminium on High-Energy Ball Milling and Spark Plasma Sintering of Silicon Nitride ", Key Engineering Materials, Vol. 287, pp. 156-159, 2005