| 摘要 |
Process for producing a ceramic body from silicon nitride and a ceramic body produced in this way. The body is inherently reinforced and has a high resistance to fracture. A mixture of powders containing silicon nitride (Si3N4), magnesium and yttrium oxides and a compound which increases the growth of β-Si3N4 whiskers, producing densification and forming β-Si3N4 whiskers in situ is hot pressed. The new Si3N4 ceramic material which has high strength and fracture resistance comprises a crystalline phase of Si3N4 with >= 20% by volume in the form of whiskers which have an average aspect ratio >= 2.5; a second vitreous phase which contains a source of magnesium, a source of yttrium, a compound which increases the growth of β-Si3N4 whiskers, and silica in a quantity <= 35% by weight; and <= 10% by weight of other phases. Applications to ceramic parts subject to wear and high temperatures.
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