Why do some tempered glass self destruct after being tempered? The reason is actually very simple. During the production process of glass, some nickel containing impurities are mixed in the melted materials such as raw materials or refractory materials. These impurities are used together during the glass melting process to form nickel sulfide crystals. Nickel sulfide crystals are in the alpha phase at temperatures above 380 ℃ and in the beta phase at room temperature. When nickel sulfide crystals transition from the alpha phase to the beta phase, the volume of the crystals will change by 2-4%, and the average diameter of the nickel sulfide crystals that cause tempered glass to self destruct is 0. About 2mm. During the formation of raw glass in glass factories, a slow annealing process is required, and nickel sulfide crystals will not significantly affect the strength of the glass. But when tempering glass, the situation is very different.

Due to the quenching process used for tempered glass. Under the action of cooling air, the cooling rate of glass is very fast. When the glass cup is cooled to room temperature and the structure is completely fixed, the α phase nickel sulfide crystals have not yet had time to transform into the low-temperature β phase, and still exist in the high-temperature α phase. If nickel sulfide crystals appear in the tensile stress zone of tempered glass, then as long as there is a crystal transformation, self explosion will definitely occur.
Due to the unpredictable time of crystal transformation, the self explosion of tempered glass at room temperature is also completely uncertain. Reduce the probability of self explosion. The solution to the self explosion of tempered glass is to homogenize the tempered glass (that is, to reheat the tempered glass to 280-300 ° C and keep it warm for 2-4 hours, so that the tempered glass that is capable of self explosion can burst during this process).
The homogenization of tempered glass is also known as the treatment of tempered glass or the hot-dip treatment of tempered glass. According to the analysis of the glass factory, after strict homogenization treatment, the probability of self explosion of tempered glass will be greatly reduced, with less than one percent of Galen glass experiencing one self explosion per 10000 square meters per year. This kind of tempered glass can be called true safety glass.