What are the causes of black silicon carbide powdering
Author:admin Addtime:2020-08-29 10:06 Click:℃
Black silicon carbide itself is used as abrasive. If it is powdered, it is almost the same as the waste product, which can not play the original role. This may be caused by the long storage time or the low silicon content. For details, please refer to the following knowledge:
During the storage of black silicon carbide, the humidity of the air is too high, or when it comes into contact with water, the impurity content of aluminum, calcium and phosphorus is high. After a period of time, the phenomenon of pulverization may occur. The phenomenon of pulverization will lead to the odor of ferrosilicon. This odor is toxic, and in serious cases, it will cause combustion and other phenomena.
If the content of Al, P and Ca is not proper, the black silicon carbide will be powdered. When the content of aluminum and phosphorus increases to a certain value, it is easy to produce pulverization in the air with high humidity. The silicon content of black silicon carbide has been observed and studied in some units. It is preliminarily considered that low silicon content (mostly waste products) tends to pulverize. The reason may be that the temperature of FeSi, FeSi2 and other silicon and iron compounds in ferrosilicon decreases and volume expansion, resulting in pulverization. The main reason for the pulverization of ferrosilicon with aluminum content is the formation of aluminum hydroxide and gas.
After pouring, the cooling rate of black silicon carbide is also related to the size of silicon segregation. The faster the cooling speed is, the smaller the segregation degree is, the easier to produce pulverization. If the cooling speed is slow, it is related to the thickness.
Through the above knowledge, it is not difficult to see that the use of black silicon carbide needs to meet a lot of conditions, so we must polish our eyes when buying, let the manufacturer show the data report.