METHOD OF OBTAINING SURFACE COATINGS OF SILICON NITRIDE (SI3N4) ON CERAMIC COMPONENTS AND PARTS

摘要

The invention relates to a method of obtaining surface coatings of silicon nitride (Si3N4) on ceramic components and parts, by impregnating the surfaces of said ceramics with silicon powder suspensions having a particle size of preferably less than 200 µm. The thickness of the coatings is dependent on the impregnation time and on the properties of the slip and the ceramic. The subsequent nitriding of the coating, comprising heat treatment at temperatures of between 1300 °C and 1500 °C in N2 atmospheres, produces a continuous coating of Si3N4. The invention can be used in silicon metallurgy and for the production of pots for melting silicon or for receiving molten silicon, tubes and channels for the transport thereof or different components for the subsequent purification of same, owing to the stability and chemical compatibility between the Si3N4 and the molten silicon.