The reasons for cracking of aluminized boron nitride crucible are as follows:
1. Quality problem of the material itself: If there are defects in the production process of the boron nitride crucible or the material quality is not good, it will be damaged at high temperature. It is easy to cause cracking due to excessive thermal stress in the environment.
2. The aluminum plating temperature is too high: If the aluminum plating temperature is too high and exceeds the limit temperature that the boron nitride crucible can withstand, it will easily cause excessive thermal stress and lead to cracking.
3. The aluminum plating time is too long: If the aluminum plating reaction time in the boron nitride crucible is too long, it may cause excessive aluminum deposition inside the crucible, which may lead to cracking.
4. Improper cooling method: If the boron nitride crucible is rapidly cooled down by rapid cooling methods such as water immediately after the high-temperature reaction is completed, it may also lead to cracking.