Seeded silicon nitride

Hirao K, Imamura H, Watari K, Brito ME, Toriyama M, Kanzaki S (1999) Seeded Silicon Nitride Microstructure and Performance. In Niihara K, Sekino T, Yasuda E,... 

K. Hirao, H. Imamura, K. Watari, M. E. Brito, M. Toriyama and S. Kanzaki, Seeded Silicon Nitride Microstructure and Performance , Key Engineering Materials, 161-163, 1999, 469-474,... 

Figure 8.4 Fracture tough ness and strength ofthe seeded silicon nitride as a function of amount of 3-seed costal addition. Reprinted with permission from Ref. [15] 1994, Blackwell Publishing, Inc.

Seeding technique, procedure 130, 131 Sequential addition of monomers 164, 167 Silicon-carbide fibers 8 Silicon-nitride fibers 8 Silicone rubber, crosslinked 4, 7-9, 31, 67 Siloxane, definition of 5 Siloxane-acrylate copolymers 27, 29, 56, 57, 64, 70, 71, 73, 74... 

Microstructures of the two GPS-ed silicon nitride materials (a) SN-F (not seeded, cold pressed), (b) SN-C (seeded, tape cast). Plasma etching highlights the epitaxial growth of P-sialon on P-Si3N4 cores (indicated by the arrows). 

SN-F, Silicon nitride without seeds 3247 <1 0.3/0.6, nearly bimodal... 

K. Hirao, T. Nagaoka, M. E. Brito and S. Kanzaki, Microstructure Control of Silicon Nitride by Seeding with Rodlike P-Silicon Nitride Particles , J. Am. Ceram. Soc., 77, 1994, 1857-62. 

Figure 8.2 Fibrous crystals of silicon nitride seeds. Illustration courtesy of Yoshiaki Inagaki et al.

Figure 8.3 Microstructure of the silicon nitride where the 2 vol% of p-seed c stals was dispersed into the raw powders of a-phase and sintering additives before sintering. Note the bimodal distribution of silicon nitride grains. Illustration courtesy of Kiyoshi Hirao, et al.

Figure 8.5 Schematic illustration of fabrication procedure for silicon nitride with controlled grain orientation through seeding and tape casting. Reprinted with permission from Ref [19] ...

Figure 8.6 shows the microstructure of the seeded (2 vol%) and tapesilicon nitride. Flere, the large fibrous grains with a diameter of a few micrometers and a... 

Another feature of this material is its narrow distribution of the fracture strength. When the strength distribution was expressed in Weibull statistics, the Weibull modulus was 46 - substantially higher than the value of 26 obtained for a conventional, self-reinforced silicon nitride. Thus, the seeded and tape-cast silicon nitride showed a synergistic improvement in all of the important fracture attributes, such as fracture strength, fracture toughness, and strength stability (Weibull modulus). 

Figure 8.9 Microstructures of silicon nitrides, (a) a-powder with 2 wt% 3-seed crystals, tape-cast and gas-pressure-sintered at 1850°C for 6 h (b) a-powder without 3-seed crystals, hot-pressed at 1750°Cfor2 h (c) a-powderwithout...

Figure 8.14 Fracture toughness and strength for various silicon nitrides studied so far. papers. The filled circles (a) denote the self-reinforced material [3, 22, 38] the filled triangle (b) denotes the seeded and tape-cast material [19] the open triangle (c) denotes...

Figure 8.16 R-curve behaviors determined by the AMDCB techniques for the seeded and tape-cast silicon nitrides with additives of 6.25 wt% Y2O3-1.0wt% AI2O3, 5wt%...

Figure 8.18 Microstructure of the silicon nitride fabricated through dispersing 3 wt% of P-seed crystals into the raw powder slurry of a-phase and Lu203-Si02 sintering additives and subsequent tape-casting, (a) Plane parallel...

Figure 8.19 Fracture strength and fracture energies at room temperature (R.T.) and 1500°C of the seeded and tape-cast silicon nitride with Lu203-Si02 sintering additives and reference material (unseeded but otherwise...

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