PROCEDURE FOR MANUFACTURE OF DENSE CERAMICS BASED ON NIOBATES AND NIOBATES-TANTALATES OF ALKALINE ELEMENTS

摘要

The subject of invention is the procedure of preparation of dense ceramics from niobates and niobates-tantalates of alkaline elements with addition of potassium and sodium germanate. The ratio of potassium to sodium germanate is optional, however preferentially the same as the ratio of potassium to sodium in niobate-tantalate of alkaline elements, and the quantity of additive is in the range of 0.1 to 10 weight %. The mole ratio of K/Ge to Na/Ge within the potassium and sodium germanate additive lies between 2/2 and 1/2. The niobate and alkaline element niobate-tantalate powders are mixed, potassium and sodium germanate are added, the mixture is wet-ground, the suspension dried out and the powder pressed into shapes and fired at a temperature between 950 and 1500 degrees Celsius for 1 to 24 hours. Density of ceramics amounts to more than 95 % of its theoretical value.