A company overseas has successfully developed a billet for low-temperature firing ceramics. It is said that this blank can be porcelainized at a low temperature of 900 °C.
Ceramics are usually made of kaolin, clay, feldspar, etc., and sintered at a high temperature higher than 1000 °C. The low-temperature fired ceramic ingot developed by the high-grade kaolin is 62-82% (based on the anhydrous state after burning), and the calcium carbonate having an average particle diameter of 1.5/μ or less (to the cao content after burning) 18 to 38% and borosilicate glass powder 1 to 30% are base materials, and pigments, organic additives, etc. are added as needed.
The billet is formed into a billet, and can be sintered at a low temperature of 900 ° C. Even if the temperature is raised to 1200 ° C, the film is not softened and deformed, and the firing temperature range is extremely wide. After firing, the glaze can be applied and the second firing can be performed.
Studies have shown that, on the one hand, in the calcination process, the solid solution between the thermal decomposition and decomposition products of kaolin and calcium carbonate is simultaneously carried out, and the formation of solid solution before precipitation of silicate crystals in the temperature range of 800 to 900 °C The basic result, and the product at this stage is a product of a collection of amorphous fine particles containing an appropriate amount of cao, which is maintained in a shape with extremely high viscosity while maintaining low-temperature sinterability, and is formed dense structure at 875 to 950 ° C.
Further, in the firing stage, the densification sintering temperature is further lowered by the presence of the borosilicate glass granules, and the densification is performed at 900 ° C to form a densification, and the green body is not cracked, and a ceramic having a water absorption rate of almost zero is obtained. It is reported that this research result has been patented.