Relationship between the Thermostability of CBN and Its Crystal Shape and Crystallinity

Thermostability is one of the important indexes of CBN. This paper studied the relationship between the thermostability of CBN and its crystal shape and crystallinity by using mineral microscope and DTA. It is found that, CBN crystals with perfact shape, clear planes and transparent have high thermostatility. Those with micropores on the crystal plane have lower crystallinity and thus lower thermostability. By means of reflecting microscope, we can test the thermostatility of CBN, quickly and reliably.