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A process for the production of reinforced refractory composite structures which may be of high density and shaped in desired three dimensional configurations. The shaped composite structures are produced by forming a suspension of particulate materials including a colloidal refractory power, colloi

A process for the production of reinforced refractory composite structures which may be of high density and shaped in desired three dimensional configurations. The shaped composite structures are produced by forming a suspension of particulate materials including a colloidal refractory power, colloidal sintering aid, and refractory reinforcement whiskers in a carrier liquid. The colloidal suspension is conformed to a desired configuration and brought into contact with a semipermeable membrane. A pressure is imposed on the suspension in the desired configuration to expel liquid from the suspension through the membrane to arrive at a green composite having a density of at least 40% of theoretical density. After drying, the green composite is then sintered under conditions to form an intergranular liquid phase in the composite providing further densification. A specific composite is a silicon carbide reinforced silicon nitride composite. The green composite may be sintered to provide a density of at least 93% of theoretical to produce a closed impermeable composite surface. The composite may then be subjected to hot isostatic pressing.

대표청구항 ▼

In a method for producing a whisker reinforced refractory composite, the steps comprising: (a) forming a suspension in a carrier liquid of a mixture of particulate materials comprising a colloidal refractory matrix powder, a colloidal sintering aid and refractory reinforcing whiskers; (b) conforming

In a method for producing a whisker reinforced refractory composite, the steps comprising: (a) forming a suspension in a carrier liquid of a mixture of particulate materials comprising a colloidal refractory matrix powder, a colloidal sintering aid and refractory reinforcing whiskers; (b) conforming said suspension to a desired configuration and into contact with a semi-permeable membrane; (c) retaining said suspension in said configuration while imposing a pressure on said suspension to expel liquid from said suspension through said membrane to arrive at a green composite shaped in said desired configuration and having a density equal to at least 40% of the theoretical density of said composite; (d) drying said green composite; and (e) thereafter sintering said shaped dried composite under an nonoxidative atmosphere at a temperature sufficient to form an intergranular liquid phase in said composite.