A self-reinforced silicon nitride ceramic of high fracture toughness and a method of preparing the same

摘要: A process for preparing a self-reinforced silicon nitride ceramic body of high fracture toughness comprising hot-pressing powder mixture containing nitride, magnesium oxide, yttrium oxide and compound which enhances growth beta-silicon whiskers under conditions such that densification the in situ formation having aspect ratio occur. novel strength is disclosed crystalline phase wherein at least 20 volume percent form an average 2.5; glassy second source magnesium, e.g., yttrium, compound, as titanium dioxide, niobium diboride or strontium whiskers, silica total amount not greater than 35 weight percent; 10 other phases. The may also include up to 5.0 percent, based upon ceramic, aluminium boron nitride.