METHOD OF MAKING SILICON NITRIDE CERAMIC WITH CALCIUM ALUMINATE SINTERING ADDITIVE WITH LOW MELTING Russian patent published in 2020 - IPC C04B35/593 

FIELD: metallurgy.

SUBSTANCE: invention relates to powder metallurgy. Disclosed method of producing ceramic material based on silicon nitride involves preparing a charge by mixing α-nitride of silicon with low-melting additive of calcium aluminate, addition of organic plasticizer to the mixture and preliminary moulding of workpieces for hot pressing. Hot pressing is carried out at temperatures of 1450–1650 °C, pressing pressure 30 MPa, holding for 60 minutes. Use of a sintering additive of calcium aluminate with eutectic composition provides its earlier melting, its interaction with silicon nitride and crystallization of the inter-grained phase of Ca-sialon. Firing temperature when using the proposed additive is 1450–1650 °C, which is 100–400 °C is lower than that of analogues, at that, main mechanical and high-temperature properties are preserved.

EFFECT: invention can be used for making ceramic structural parts, for example, in the manufacture of sliding bearings or cutting tools.

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