Provided are a molding step (A) of preparing an alumina molded body 11 from a molding raw material which contains an alumina raw material powder having an average particle size of 2 m to 5 m and a molding additive, and a sintering step (B) of preparing an alumina molded body 12, which becomes a spark plug insulator 1, by sintering the alumina molded body 11. At the sintering step (B), the alumina molded body 11 is conveyed to a continuous furnace 100 provided with a heating zone Z1 which is heated to 700 C. to 1600 C. by a heating means 401, followed by introducing oxygen gas to control the heating zone Z1 to have a high oxygen atmosphere with an oxygen concentration exceeding 20 mol %.

Provided are a molding step (A) of preparing an alumina molded body 11 from a molding raw material which contains an alumina raw material powder having an average particle size of 2 m to 5 m and a molding additive, and a sintering step (B) of preparing an alumina molded body 12, which becomes a spark plug insulator 1, by sintering the alumina molded body 11. At the sintering step (B), the alumina molded body 11 is conveyed to a continuous furnace 100 provided with a heating zone Z1 which is heated to 700 C. to 1600 C. by a heating means 401, followed by introducing oxygen gas to control the heating zone Z1 to have a high oxygen atmosphere with an oxygen concentration exceeding 20 mol %.

The invention relates to a method of controlling a ceramic and/or metal powder press (1) for pressing a compressible material (6), wherein at least one electromotive drive (15, 16; 20, 21), which adjusts at least one punch (5; 4) along a pressing direction, is controlled in such a manner that the drive (15, 16; 20, 21) moves the punch (5; 4) along a setpoint positioning path (as1) and the drive is readjusted if it deviates from the setpoint positioning path (as1), wherein a measured force (F11, F12) acting on the compressible material (6), the punch (4) or its supporting components (17-19), is used as at least one control variable for readjustment. The invention also relates to a ceramic and/or metal powder press (1) configured to carry out the method.

The invention relates to a method of controlling a ceramic and/or metal powder press (1) for pressing a compressible material (6), wherein at least one electromotive drive (15, 16; 20, 21), which adjusts at least one punch (5; 4) along a pressing direction, is controlled in such a manner that the drive (15, 16; 20, 21) moves the punch (5; 4) along a setpoint positioning path (as1) and the drive is readjusted if it deviates from the setpoint positioning path (as1), wherein a measured force (F11, F12) acting on the compressible material (6), the punch (4) or its supporting components (17-19), is used as at least one control variable for readjustment. The invention also relates to a ceramic and/or metal powder press (1) configured to carry out the method.

A sensor element and a method for producing a sensor element are disclosed. In an embodiment a sensor element includes a ceramic carrier having a top side and an underside, a respective NTC layer arranged on the top side and on the underside of the carrier and at least one electrode, wherein a resistance of the respective NTC layer depends on a thickness and/or geometry of the respective NTC layer.

A sensor element and a method for producing a sensor element are disclosed. In an embodiment a sensor element includes a ceramic carrier having a top side and an underside, a respective NTC layer arranged on the top side and on the underside of the carrier and at least one electrode, wherein a resistance of the respective NTC layer depends on a thickness and/or geometry of the respective NTC layer.

A method for producing microencapsulated fuel pebble fuel more rapidly and with a matrix that engenders added safety attributes. The method includes coating fuel particles with ceramic powder; placing the coated fuel particles in a first die; applying a first current and a first pressure to the first die so as to form a fuel pebble by direct current sintering. The method may further include removing the fuel pebble from the first die and placing the fuel pebble within a bed of non-fueled matrix ceramic in a second die; and applying a second current and a second pressure to the second die so as to form a composite fuel pebble.

A method for producing microencapsulated fuel pebble fuel more rapidly and with a matrix that engenders added safety attributes. The method includes coating fuel particles with ceramic powder; placing the coated fuel particles in a first die; applying a first current and a first pressure to the first die so as to form a fuel pebble by direct current sintering. The method may further include removing the fuel pebble from the first die and placing the fuel pebble within a bed of non-fueled matrix ceramic in a second die; and applying a second current and a second pressure to the second die so as to form a composite fuel pebble.

To provide a scale which makes it possible to adjust the temperature of a furnace so that a ceramic blank can be properly heated even if various conditions such as the combination of the used ceramic blank and investment, and the type and size of the furnace vary, the scale comprises: a scale part; and a base part, the scale part and the base part being formed of wax or resin, wherein the base part has a shape of protruding from part of the scale part, a size of the scale part is larger than that of the base part in a direction orthogonal to a protruding direction of the base part.

Each of a plurality of divided dies (11, 12) has a divided surface (111, 121) and a defining surface (112, 122) which defines a cavity 100. The divided surface has an inclined divided surface (1112, 1212) inclined with respect to the translational direction, and at least one pair of perpendicular divided surfaces (1112, 1113, 1211, 1213) which is disposed on the opposite side based on the defining surface and is perpendicular to the translational direction. Each of the plurality of divided dies (11) and (12), while abutting against each other at, at least the at least one pair of perpendicular divided surfaces of the divided surface, abuts against each other in a state of being spaced apart from each other with a gap d within a range of 1 to 30 m at the inclined divided surface (1112, 1212), thereby forming the cavity 100.