Silicon nitride is the most advantageous in the field of high temperature application silicon nitride ceramics hardness 1400~1600Hv.
Preparation of silicon nitride
Process and method: Spray granulation method usually adopts centrifugal or pressure spray granulation equipment to stir and granulate the mixed silicon nitride slurry, so that the silicon nitride powder is evenly distributed, thus improving the sphericity of silicon nitride particles and the fluidity of powder. In the process of spray granulation, factors such as temperature, pressure, feed rate, stirring time and binder type have an important impact on the particle size and dispersion of silicon nitride powder after granulation. However, the morphology of spray granulation particles is not easy to control, and defects such as hollow and surface pits are easy to appear. In addition, the powder obtained by spray granulation usually needs to be burned of organic matter. To ensure the complete removal of organic matter so as not to affect the sintering properties of silicon nitride ceramics, it is very important to formulate a reasonable glue discharge system and accurately control the glue discharge process.
Silicon nitride medical inorganic nonmetallic materials how to classify
Silicon nitride ceramics melting point 1900℃(under pressure). Thermal expansion behavior is an extremely important factor affecting the thermal shock resistance of materials. Moreover, according to the thermal expansion theory of materials, we can design and adjust the thermal expansion behavior of materials to a certain extent, such as the size of the thermal expansion coefficient of zirconia and the type of stabilizer and the amount of addition have a certain relationship. Therefore, to examine the thermal shock resistance of materials, its thermal expansion behavior should be taken as the research weight Dot.
Application of silicon nitride in biology
Mechanical ceramic silicon nitride is heat resistant and can still maintain high strength and stiffness at 1400 (but its mechanical strength decreases when it exceeds 1200, but it is relatively brittle). Reinforced ceramics reinforced with continuous fiber can be applied to turbine components, especially ceramic blades, turbine outer rings and air bearings of small engines. In addition, the proportion of silicon nitride ceramics is small, only 41% of steel bearings, which can effectively reduce the weight of aircraft engines and reduce fuel consumption.