What is the minimum operating temperature for silicon nitride bearings?

Silicon nitride can also be used at liquid nitrogen temperatures (minus 196°C).

Silicon nitride ceramic balls are precision ceramics sintered at high temperature in a non-oxidizing atmosphere. They have high strength, high wear resistance, high temperature resistance, corrosion resistance, acid and alkali resistance, can be used in seawater for a long time, and have electrical and magnetic insulation properties. good performance. At 800 ℃, the strength and hardness are almost unchanged, and its density is 3.20g/cm3, which is almost 1/3 of the weight of bearing steel, and the centrifugal force is small during rotation. High-speed operation can be achieved. It also has self-lubricating properties, and it can be used in environments with high pollution without lubricating media. Be the first choice for ceramic bearings and hybrid ceramic ball bearings.

For many years, ceramic materials have been of greatest interest to engineers working on bearings. The term "ceramic bearings" usually conjures up bearings made entirely of ceramic that run red and hot without lubrication. Much of the early work focused on all-ceramic bearings in high temperature environments, such as air turbine engine bearings. There is ongoing work on such bearings, but the lubrication system needs to be improved. Recent development work has focused on hybrid bearings consisting of steel rings or raceways and ceramic balls. Hybrid bearings have been used in such urgent applications as machine tool spindles, and their use is becoming more and more extensive.

There are many kinds of ceramic materials with different compositions, microstructures and properties. It has been proved that silicon nitride material has the best physical and mechanical comprehensive properties when used in bearings. At present, the annual production of silicon nitride balls in the world is estimated at several million pieces.