SHS of α-Si3N4 from fine Si powders in the presence of blowing agents

Salt-assisted combustion synthesis of silicon nitride with high α-phase content

“…The importance of silicon nitride ceramics has stimulated the development of production methods for Si 3 N 4 powders. These methods include direct nitridation of silicon [5][6][7][8], carbothermic reduction of silica in nitrogen atmosphere [9,10], diimide synthesis [11,12], vapor phase synthesis [13], and combustion synthesis (CS) [14][15][16][17].…”

“…These salts generally sublime at relatively low temperatures to produce a "fluffy" effect that enhances the nitridation process. Most studies agree that high ␤-phase content Si 3 N 4 is the major product formed during silicon nitridation by combustion; however, the bibliography of patents and scientific reports indicates that the addition of ammonium halides can promote ␣-phase formation [14,25]. Cao et al reported that sodium azide (NaN 3 ) is useful in the preparation of Si 3 N 4 whiskers with 80% ␣-phase content [22].…”

Gel-cast-foam-assisted combustion synthesis of elongated β-Si3N4 crystals and their effects on improving the thermal conductivity of silicone composites

“…Si 3 N 4 powder itself is the most used diluent. Its addition usually ranges from 20 to 60 wt.% [15][16][17][18][19][20]. The poor homogeneity of the products, on the other side, is owing to the nonuniform and unstability of the green compacts and the uncontrollable reaction rate.…”

Formation and evolution of quasi-aligned AlN nanowhiskers by combustion synthesis

“…Shi). developed for synthesis of pure AlN powder [11][12][13][14]. However, since the high thermal-gradient and fast reaction speed in the CS process, the morphology of the AlN product was difficult to control and often consists of various grain morphologies [4,[15][16][17] (agglomerated particles, whiskers, faceted particles, rods, pyramids, etc.…”