High temperature enamel and alumina ceramic material for insulation spiral heater spherical ionizer of mass spectrometers

Development of ceramic insulating materials with the coefficient of temperature linear expansion, equal to the coefficient of temperature linear expansion (CTLE) of isolated details is of high importance nowadays. This article concerns questions of definition of high-temperature enamel and isolating ceramic material composition. Dependences of ceramic material shrinkage on the size of particles of oxide of aluminum are defined, the optimum sizes of these particles and a ratio between firm and liquid components in the course of roasting are found. Annealing of the suggested material results into a two-phase system consisting of grains of aluminum oxide with particles size of 20…25 microns and a glass phase of structure of Аl2О3, SiO2, В2О3 and Na2О with initial size of particles within 1…2. As a result of the conducted study the following conclusions may be drawn: the developed composition of high-temperature enamel provides reliable isolation of ionizers cases for mass spectrometers from heating elements; and the composition of an isolating ceramic material provides equality of CTLE of ceramics, of a material of the case and a heater spiral, and also no-shrink condition at agglomeration.