Si3N4 -SiC Whisker Composite Material

Effects of filament-matrix interfaces on the mechanical properties of SiC-reinforced Si sub 3 N sub 4: A Review

“…This phenomenon has been observed in SiC-filament-reinforced Si 3 N 4 prepared by hot pressing and injection molding Kobayashi, Kandori, and Wada 1986). Preferred orientation of SiC whiskers in slip cast Si 3 N 4matrix composites has also been reported by , whereas reported random orientation of SiC whiskers in similar slip (a) Hayami et al 1986;Ueno and Toibana 1983;Corbin 1987. (b) Mangels 1977;Mazdiyasni, West, and David 1978;Lundberg et al 1986 andBaumgartner 1978;Birch, Wilshire, and Godfrey 1978;Sheldon and Haggerty 1988;Haggerty et al 1988;Takao, Cannon, and Danforth 1986;Koczak andBarsoum 1988.…”

“…Extensive evaluation of the mechanical properties of Tokai-whiskerreinforced s; 3 N 4 (a) at temperatures between room temperature and 1300°C was reported by Hayami et al (1986) and Ueno and Toibana (1983). Samples were prepared by hot pressing using two types of sintering aids: v 2 o 3 -Al 2 o 3 , and v 2 o 3 -La 2 o 3 .…”

“…(b) In addition, tensile strengths at room temperature and 1300QC are reported to be greater for unreinforced Si 3 N 4 , as opposed to reinforced Si 3 N 4 . Specifically, the maximum tensile strength for unreinforced material at room temperature is reported to be 1050 MPa, whereas filament-reinforced material of similar matrix composition is only 650 MPa (Ueno and Toibana 1983;Hayami et al 1986). At 1300'C, the same unreinforced and reinforced materials exhibit tensile strengths of approximately 750 MPa and 600 MPa, respectively (Ueno and Toibana 1983;Hayami et al 1986).…”

“…However, most of these discussions are brief, and exhaustive correlations among macroscopic physical properties, chemical equilibria at the interface, and thermo-mechanical stresses at the interface have only been performed in a Buljian 1987;Buljian et al 1987 and !988;Buljian, Baldoni, and Huckabee 1987. Rice et al Jg80;Bender et al 1978;Lundberg et al !987;Shetty et al 1985;Shalek et al 1986;Hayami et al 1986;Ueno and Toibana 1983; few of these references. The most pertinent references are discussed in further detail in the following sections.…”

Microstructure / mechanical-property relationships and R-curve behavior in Si{sub 3}N{sub 4}/Si{sub 3}N{sub 4}(w) composites

“…Silicon nitride (Si3N4) is one of tile most widely studied structural ceramic material because of its potential for high strength and toughness. Several studies have been conducted to improve its toughness by SiC-whisker additions [1][2][3]. However, in many cases, satisfactory improvements in pro.perti es were not achieved because of the adverse interfacial reactions between the whiskers and matrix.…”