SU381644A1 - METHOD OF OBTAINING A VACUUM-BLACK FORSTERITE CERAMIC MATERIAL - Google Patents

Description

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The invention relates to the technology of manufacturing vacuum forsterite ceramics, which can be used in the electrovacuum industry as shells of titanium ceramic lamps.

A known method for producing a vacuum-tight forsterite ceramic material based on talc, oil oxide, barium carbonate and bentonite is introduced into the mixture of mineralizers, which can be used to form them as a result of burning the glassy phase of the material.

However, the increased content of the glassy phase of the material leads to a deterioration in the physicotechnical properties of forsterite ceramics, and its sintering temperature remains quite high (above 1350-1360 ° C) - beyond the limits of the possibility of furnace equipment with silyte heaters.

To reduce the sintering temperature of the material while preserving its dielectric and mechanical properties, a method is proposed in which the additive of strontium oxide is preliminarily introduced into magnesium oxide, beryllium in amounts of 0.2-1.0% of the weight of magnesium oxide and calcined at a temperature of 500-800 ° WITH. The material is obtained in the following way. Magnesium oxide is mixed with an aqueous solution of strontium nitrate or beryllium, dried and calcined at a temperature of 500 ° C. The dried and granulated mixture is burned at 1300 ° C with a holding time of two hours. The resulting spec is ground and decorated with 13 products.

method of hot pouring under pressure. Firing products to a vacuum-tight state (bulk weight 2.93-Z.bb g / s. For LF-P ceramics) is carried out at 1270-1300 ° C. By its mechanical and dielectric properties

the resulting material is not inferior to forsterite ceramics LF-P, obtained by conventional technology, whereas the sintering temperature of the latter is 1340-1360 ° C.

Subject invention

A method for producing a vacuum-tight forsterite ceramic material by burning a mixture based on talc, magnesia, bentonite and barium carbonate, characterized in that, in order to reduce the sintering temperature of the material while preserving its dielectric and mechanical properties, an oxide addition is preliminarily introduced into magnesia, for example , strontium, beryllium in the amount of 0.2-1.0% by weight of magnesium oxide, and the mixture is calcined at a temperature of 500-800 ° C.