ceramic crucible is a cup-shaped vessel used in the chemical industry. It was first used in alchemy experiments to hold liquids or solids.High temperature heating is the basis for ensuring the smooth progress of the chemical reaction. The material of the crucible is required to be heat-resistant, strong, and not occur chemical reactions at high temperatures ,the earliest crucibles in history were made of clay, and in modern times,ceramic crucible can be developed by any melt or change its contents material, such as quartz ceramics, corundum, boron nitride, zirconia, graphite, and metals such as platinum, nickel,and chromium.

Among them,bn ceramics is an advanced ceramic material with broad application prospects. boron nitride crucible is a crystal composed of nitrogen atoms and boron atoms, with a chemical composition of 43.6% boron and 56.4% nitrogen, in four different variants: hexagonal boron nitride (HBN),cubic boron nitride (CBN),rhombohedral boron nitride (RBN), wurtzite boron nitride (WBN).

Since the boron nitride ceramics has a thermal expansion coefficient comparable to quartz, but the thermal conductivity is 10 times than quartz, the thermal shock resistance is is quite good, bn crucible can reduce the risk of cracking due to rapid temperature changes, and it is no problem to cycle several times at 20~1200℃. In addition, boron nitride crucibles does not react with acids,alkalis, glass and most metals, and has low mechanical strength, only slightly higher than  graphite, but will not soften under load at high temperatures.boron nitride crucible can be processed by general metal processing machines, so it is indeed suitable for crucibles of evaporating metals, utensils, and liquid metal conveying pipes and  and moulds for cast steel.