Home > News > Silicon nitride ceramic production methods and other purposes

Silicon nitride ceramic production methods and other purposes

wallpapers News 2020-05-18
There are two production methods of silicon nitride ceramic products, reaction sintering and hot pressure sintering. The reaction sintering method is to form the silicon powder or the mixture of silicon powder and silicon nitride powder according to the general ceramic production method. Then in the nitriding furnace, pre-nitriding at 1150~1200℃, after obtaining a certain strength, can be carried out mechanical processing on the machine tool, and then further nitriding at 1350~1450℃ for 18~36h, until all into silicon nitride. The resulting product is precise in size and stable in volume. The hot pressing sintering method is to combine si3n4 powder with a small amount of additives (such as MgO, Al2O3, MgF2, AlF3 or Fe2O3, etc.) and sintering under the pressure of over 19.6mpa and 1600~1700℃. Generally, the products produced by hot pressing sintering method have higher density and better performance than those produced by reaction sintering. The properties of silicon nitride ceramics produced by these two methods.
Other applications
Silicon nitride ceramic material has high thermal stability, strong oxidation resistance and high dimensional accuracy. Because of the silicon nitride is the covalent compound high bond strength, and oxide film formed in the air, and so also has good chemical stability, oxidation under 1200 ℃, 1200 ~ 1600 ℃ generated protective film to prevent further oxidation, and is not aluminum, lead, tin, silver, brass, nickel and so on many kinds of molten metal or alloy by infiltration or corrosion, but can be magnesium, nickel chromium alloy, such as stainless steel liquid and the corrosion.
Silicon nitride ceramic materials can be used in high temperature engineering parts, metallurgy industry and other aspects of advanced refractory materials, chemical industry corrosion resistant parts and sealing parts, machining industry tools and cutting tools.
Because silicon nitride can form a strong combination with silicon carbide, alumina, thorium dioxide, boron nitride, etc., it can be used as a bonding material and modified in different proportions.
In addition, silicon nitride can be used in solar cells. After the silicon nitride film is plated by PECVD method, it can not only reduce the reflection of incident light as an anti-reflection film, but also play a role of passivation defect in the deposition process of silicon nitride film, when hydrogen atoms of the reaction products enter into the silicon nitride film and silicon wafer. The atomic number ratio of silicon nitride to silicon nitride is not strictly 4:3, but fluctuates within a certain range according to the different process conditions, and the physical properties of the films corresponding to different atomic ratios are different.
Used for ultra high temperature gas turbine, aircraft engine, electric furnace, etc.

Say something
  • All comments(0)
    No comment yet. Please say something!
Tag: Silicon nitr