Production of beta-alumina ceramic articles and furnace therefor

In a method of producing a beta-alumina ceramic article of elongate form comprising the steps of forming a shape of compressed powder of a composition which on sintering will result in a beta-alumina ceramic, and then moving the shape continuously lengthwise through a tubular furnace in the direction of the longitudinal axis thereof to thereby result in the formation of water vapor and a stable atmosphere of sodium oxide vapor and so that a short part of the length of the shape is raised to the sintering temperature with the heated zone gradually moving along the length of the material to be fired, the maximum temperature being a sintering temperature between 1550.degree. C and 1900.degree. C, the improvement comprising simultaneously causing an air flow through the tubular furnace in the direction of movement of the shape at a speed not less than the speed of movement of the shape while moving said shape through said furnace, said air flow being sufficient to carry said water vapor through said furnace but not so great that said sodium oxide is carried through said furnace faster than said sodium oxide is formed.

In a method of producing beta-alumina ceramic articles comprising the steps of forming shapes of compressed powder of a composition which on sintering will result in a beta-alumina ceramic, and then moving a set of these shapes continuously through a tubular furnace in the direction of the longitudinal axis thereof to thereby result in the formation of water vapor and a stable atmosphere of sodium oxide vapor and in order to sinter said powder, the improvement comprising simultaneously causing an air flow through the tubular furnace in the direction of movement of the shapes while moving said shapes through said furnace, said air flow being sufficient to carry said water vapor through said furnace but not so great that said sodium oxide is carried through said furnace faster than said sodium oxide is formed.

In a method of producing beta-alumina ceramic articles of elongate form comprising the steps of forming shapes of compressed powder of a composition which on sintering will result in a beta-alumina ceramic, and then moving a set of these shapes continuously lengthwise through a tubular furnace in the direction of the axis thereof to thereby result in the formation of water vapor and a stable atmosphere of sodium oxide vapor and so that a short part of the length of the shapes is raised to the sintering temperature with the heated zone gradually moving along the length of the shapes to be fired, the maximum temperature being a sintering temperature between 1550.degree. C and 1900.degree. C, the improvement comprising simultaneously causing an air flow through the tubular furnace in the direction of movement of the shapes at a speed not less than the speed of movement of the shapes while moving said shapes through said furnace, said air flow being sufficient to carry said water vapor through said furnace but not so great that said sodium oxide is carried through said furnace faster than said sodium oxide is formed.