Sintering silicon nitrides

Self-baking electrodes, 12 305, 755 Self-bonded reaction-sintered silicon nitride, 17 210, 211 Self-catalyzed polyols, 25 464 Self-cleaning materials, 22 108-127 problems and outlook for, 22 123-124 surface characteristics of, 22 108-109... 

M. Giirtler and G. Grathwohl, Tensile Creep Testing of Sintered Silicon Nitride, in Proceedings of the Fourth International Conference on Creep and Fracture of Engineering Materials and Structures, Institute of Metals, London, U.K., 1990, pp. 39 408. 

G. D. Quinn and W. R. Braue, Fracture Mechanism Maps for Advanced Structural Ceramics, Part 2, Sintered Silicon Nitride, /. Mater. Sci., 25, 4377-4392 (1990). 

Organosiliconcompoundssuchashexaphenylcyclotrisilazaneandmethylphenylpoly-silane are used to infiltrate porous reaction-sintered silicon nitride . The cyclosilazane is thermallty decomposed slowly and carefully in an inert atmosphere at 600-1400°C very large white whisker bundles of a-Si3N4 are synthesized . 

Quackenbush CL, French K, Meil JT (1982) Fabrication of Sinterable Silicon Nitride by Injection Moulding. J Ceram Eng Sci Proc vol 3 pp 30-34... 

In RBSN, a silicon metal powder preform reacts with nitrogen gas to form silicon nitride. The reaction occurs by percolation of the gas phase into the open porosity of the silicon preform, while the large specific volume of the silicon nitride product substantially reduces the volume fraction of residual porosity (down to a lower limit of approximately 9%), The mechanical properties of RBSN are inferior to those of sintered silicon nitride powder products, but the reduced costs of machining the near-net-shape product is a very attractive advantage. 

Material type Reaction bonded silicon nitride (RBSN) Sintered RBSN (SRBSN) Sintered silicon nitride (SSN) Gas pressure sintered silicon nitride (GPSN) Hot-pressed silicon nitride (HPSN) Sinter HIP silicon nitride (Sinter-HIPSN) HIP-ed silicon nitride HIP-SN... 

Yang W, Hojo J, Enomoto N, Tanaka Y, Inada M (2013) Influence of sintering aid on the tranlucency of spark plasma-sintered silicon nitride ceramics. J Am Ceram Soc 96 2556-2561... 

Takahashi H, Shinohara N, Uematsu K (1996) Influence of spray-dry slurry flocculation on the structure of sintered silicon nitride. J Ceram Soc Jpn 104 59-62... 

The coefficient of linear thermal expansion, specific heat, thermal diffusivity, thermal conductivity for 1-D and 2-D SiC/RBSN at four temperatures in nitrogen measured parallel and perpendicular to the fibers are summarizedin Tables III and IV. In general, through-the thickness thermal conductivity value at room temperature for SiC/RBSN composites is low when compared with a value 7 W/m-k for the unreinforced RBSN or with a value of 30 W/m-k for the sintered silicon nitrides [13]. Both weak bonding between the SiC... 

T.L Starr, D.L. Mohr, W.J. Lackey, and J.A. Hanigofsky, Continuous Fiber-Reinforced Reaction Sintered Silicon Nitride Composites, Ceram. Eng. Sci. Proc. 14, [9-10], pp. 1125-1132 (1993). 

The experiments were conducted on a vertical rotary surface grinder with a 5.5 kW motor spindle. The feed can be continuously adjusted within a range. The workpieces were made from intered sintered reaction-bonded silicon nitride (SRBSN) and cast-and-sintered silicon nitride (Si3N4). The grain size was between 0.3 and 0.4 pm for SRBSN and between 0.6 and 0.8 pm for SiaN4. Cast-iron fiber-bonded diamond wheels of 200 mm diameter were used. A Noritake AFG-M grinding fluid at a rate of 20-30 L/min was used as electrolytic fluid. 

Urashima, K., Tajima, Y, and Watanabe, M. (1992) R-curveand Fatigue behavior of Gas Pressure Sintered Silicon Nitride, in Fracture Mechanics of Ceramics, vol. 9 (ed. R.C. Bradt), Plenum Press, New York, USA, pp. 235-310. 

Figure 16.13 Relationship between thermal conductivity and four-point bending strength of various types of high-thermal conductivity Si3N4 fabricated by different routes. GPSN = gas-pressure-sintered silicon nitride SRBSN = sintered reaction-bonded silicon nitride [62].

Figure 16.15 Scanning electron microscopy images of polished and etched surfaces for (a) sintered reaction-bonded silicon nitride (SRBSN) from a fine silicon powder (b) SRBSN from a coarse Si powder (c) Sintered silicon nitride from a commercial fine-grained a-Si3N4 powder. All of the specimens were doped with...

Since the 1970s, the search for improved materials has led to a better understanding of the role of additives in the densification and microstructural development of silicon nitride-based ceramics and the consequences for final properties [1, 6]. Improvements in powder manufacture and forming techniques and the development of alternative firing processes has led to a complete family of materials including RBSN, HPSN, sintered silicon nitride (SSN), sintered reaction-bonded silicon nitride (SRBSN), gas-pressure sintered silicon nitride (GPSSN), hot isostatically pressed silicon nitride (HIPSN) and silicon nitride alloys or solid solutions termed SiAlONs, based on their elemental components. 

Sintered silicon nitride has very good wear resistance, low friction, high elastic modulus, and low density, all properties that have enabled it to be used in various wear parts and engine components including high-temperature, unlubricated roller and ball bearings shown in Fig. 1 and as turbocharger rotors as shown in Fig. 2. 

Fig. 7.5 a Static fatigue life of sintered silicon nitride at room temperature, b Cyclic fatigue life of sintered silicon nitride at room temperature [12]. With kind permission of John Wiley and sons... 

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