Ceramic Bearings, Are They Suitable For Your Application? Posted on 27 Jun 17:08
Ceramic Bearings: Pros and Cons
Ceramic bearings are light, electrically insulating and highly resistant to wear and abrasion. This makes them suitable for environments where normal chrome steel bearings fall short.
What is ceramic?
Ceramic materials are found in all kinds of art objects and utensils. We all know tiles, pans, brake discs and dental fillings. The word ceramic is derived from the Greek word kéramos, which translates as “clay” or “baked pot”. This shows the origins of ceramics; a manufacturing process that involves heating.
Ceramic materials are found in all kinds of art objects and utensils
Hybrid or all-ceramic
Ceramic bearings are lighter and more durable than ordinary steel bearings. There are several types. Hybrid bearings contain ceramic and steel components. The roller elements are ceramic balls or rollers, while the inner and outer rings are steel. There are also all-ceramic bearings without any steel parts. Often these are made of silicon nitride (Si3N4) or zirconium oxide (ZrO2). Hybrid and full-ceramic bearings offer some advantages. They are:
- Electrically insulating
- Suitable for high speeds
- Highly resistant to wear and abrasion
Hybrid bearings with ceramic rollers and/or balls with steel races
Non-Magnetic and Electrically Insulating
Ceramic materials are non-conductive. A desirable quality of bearings in generators and motors. Current flow may lead to serious damage in normal bearings. This should not happen in hybrid or all-ceramic bearings. The electrically insulating ceramic balls protect the steel rings from current penetration. Also, full ceramic bearings are non-magnetic. They are often used in medical devices.
Ceramic rollers prevent electrical current flow
Extreme corrosion resistance
Ceramic bearings and hybrid versions (with stainless steel races) are more resistant to corrosion than chrome steel bearings. They can withstand water, detergents, and certain chemicals. They can also take high temperatures. Compared to their chrome steel counterparts of the same design and dimensions, higher rotational speeds are possible. Hybrid bearings can handle higher speeds than all-ceramic bearings. In fact, their steel rings are less brittle than ceramic versions. This makes them less susceptible to sudden failure under excessive load or speed.
“Ceramic bearings are more resistant to corrosion and high temperatures.”
Longer life, less maintenance
Ceramic balls have lower density and much higher hardness than steel balls. They are very wear-resistant: small particles that enter the bearing are simply pulverized. And their very low rolling resistance, makes sure that little heat is released. Lubricants last longer that way. Hybrid bearings are also more resistant to adverse lubrication conditions than steel bearings. Fully ceramic ones can be used even without lubricants.
“They are very wear resistant and lubricants last longer.”
So why not use ceramic bearings?
Super-wear-resistant and able to withstand extreme conditions ceramic and hybrid bearings have lower load carrying capacity than their traditional chrome steel counterparts. They also have low impact resistance, so they're not suitable in shock load conditions. Because ceramic roller bodies are harder, they deform less. The result is a smaller contact ellipse. Also, the thermal shock resistance of steel models is better, so in areas which sustain extreme temperature variations...they will fail.. But above all, ceramic versions come with a hefty price tag. This is because the machining of raw materials for these bearings is complex and energy consuming. As a result, production takes a long time. So, please determine which features are important for your application before making your choice!
Looking for ceramic bearings? We'd be happy to help! Contact us at sales@intechbearing.com