Preparation of rod-like β-Si3N4 seeds with tailored morphology

Chemical reactivity of hot-pressed Si3N4–ZrB2 ceramics at 1500–1700 °C

“…Weak ␤-Si 3 N 4 phase is detected due to the MgO-Lu 2 O 3 additives. Previous study has confirmed that rare earth oxides could promote the ␣-␤ phase transformation [19]. In situ observation in the backscattered electron image reveals that the microstructure only consists of small-grain black Si 3 N 4 and large-grain white ZrB 2 .…”

Synthesis of rod-like β-Si3N4 seed crystals with tailored morphology

“…Due to the simplicity and convenience, a considerable number of works have been reported focusing on the preparation of β-Si 3 N 4 seeds by the direct heat treatment of α-Si 3 N 4 powders with [13][14][15][16][17][18][19][20] or without sintering additives [21]. In this context, production of β-Si 3 N 4 seeds with tailored morphology takes on special significance.…”

“…In this context, production of β-Si 3 N 4 seeds with tailored morphology takes on special significance. The primary approach is use of glass forming oxide additives, in which β-Si 3 N 4 grains generated through the conventional solution-precipitation route [13][14][15][16][17][18][19][20]. The grain growth kinetics of β-Si 3 N 4 strongly depends on the viscosity of liquid phase during sintering.…”

“…Previous studies are focusing on the selection of sintering additive(s) for optimizing the viscosity of liquid phase formed at the processing temperature. Most researchers [13][14][15][16][17] used yttria (Y 2 O 3 ) based additions, and it required high temperatures of 1800-1850 1C. Guo's research showed that [17] the increased Y 2 O 3 content and decreased N 2 pressure led to the increased Y adsorption and higher aspect ratio of β-Si 3 N 4 seeds.…”

“…Most researchers [13][14][15][16][17] used yttria (Y 2 O 3 ) based additions, and it required high temperatures of 1800-1850 1C. Guo's research showed that [17] the increased Y 2 O 3 content and decreased N 2 pressure led to the increased Y adsorption and higher aspect ratio of β-Si 3 N 4 seeds. Dai et al [18] produced β-Si 3 N 4 seeds with single Nd 2 O 3 or Yb 2 O 3 additions at 1650 and 1700 1C to modify the liquid phase viscosity.…”