|Silicon Nitride Positioning Pin
|High-Temperature Melting Point
|The strength of silicon nitride is very high, especially hot-pressed silicon nitride, which is one of the hardest materials in the world. It is extremely resistant to high temperatures of 1200°C without cooling down, then melts into a melt, which will be broken down until 1900°C. It decomposes and has amazing chemical corrosion resistance. Can withstand almost all inorganic acids and many organic acids. At the same time, it is a high-performance insulating material.
Due to the ceramics corrosion hardly, ceramic rolling bearings are suitable for operation under harsh conditions full of corrosive media.
●Long Service Life
Due to the density of the ceramic ball being lower than that of steel, the weight is much lighter, the centrifugal effect of the outer ring can be reduced by 40% when rotating, then the service life is longer.
●Less Affected by Temperature
Ceramic is less affected by thermal expansion and contraction than steel, so when the bearing gap is constant, the bearing can be allowed to work in an environment where the temperature difference changes more drastically.
Since the elastic modulus of ceramic is higher than steel, it is not easy to deform when subjected to force, so it is beneficial to increase the working speed and achieve higher accuracy.
|Air Pressure Sintered Silicon Nitride
In the welding process, silicon nitride has greater advantages and characteristics than other ceramic materials. The material sintered with a gas pressure of 100 Pa has strong advantages in various aspects such as anti-bending strength, high hardness, high-pressure impact resistance, and heat resistance. High-performance silicon nitride ceramic also has electrical insulation properties, which have proven to be a great advantage in various welding processes.
Comparison of silicon nitride and other materials
Although high-performance ceramics such as yttrium-stabilized zirconia have been used in the field of positioning pins for welding and alumina in the field of gas nozzles, the usage of silicon nitride as welding parts is an inevitable trend. Compared with other materials such as zirconia, alumina ceramic ceramics, KCF, DIP, etc., silicon nitride is the best choice for high-strength, high-yield, high-precision, and other use conditions in the welding process.
Process method: It uses silicon powder as the raw material, firstly uses the usual molding method to make the required shape, and performs preliminary nitridation in nitrogen and at a high temperature of 1200C, so that part of the silicon powder reacts with nitrogen to form silicon nitride. At this time, the whole body already has a certain strength. Then the second nitridation is carried out in a high-temperature furnace of 1350C ~ 1450C, and the reaction becomes silicon nitride.
Product performance: It is a super-hard material, which has lubricity and is resistant to wear: Except for hydrofluoric acid, it does not react with other inorganic acids, has strong corrosion resistance, and is resistant to oxidation at high temperatures. Moreover, it can resist the impact of cold and heat. It can be heated to more than 1,000C in the air, and it will not break if it is rapidly cooled and then heated.
Advantages: After being manufactured as welded dowel pins, the service life is 10--50 times that of conventional KCF dowel pins.