Material selection

Technical ceramics has established itself as one of the most advanced materials for high performance roller bearings and ceramic bearings; its advantages are well-known and proven. The many technical benefits and physical/high strength properties of ceramic products are mixture-dependent. (See pdf.) 
 
Gehrig® applies high-performance ceramics recipes from oxide ceramic and non-oxide ceramics. We manufacture from Oxide ceramics – like zirconium oxide (zirconia, ZrO2) and aluminum oxide (aluminum oxide, Al2O3) as well as non-oxide ceramics such as silicon nitride (Si3N4, Si3N4-HIP) and silicon carbide (SiC). For roller bearing technology we mainly utilize tetragonal-part stabilised ZrO2-PSZ, tetragonal-stabilised ZrO2 and Si3N4-engineering ceramic. Pressure-sintered Si3N4-HIP is used for machine components with high mechanical loads. The components are formed from a fine ceramic powder, then compressed in a sintering furnace at 1600°C degrees. Depending on the ceramic material and the specification or required tolerances, it can be finished by grinding, honing, lapping and polishing. Components made of highly pure (over 99%) aluminum oxide Al2O3 are mainly used in applications of high mechanical loads and potentially abrasive conditions, e.g. in the case of a wire and thread guide.

For hybrid bearings we mainly use corrosion-resistant stainless steels in conjunction with ceramic rolling elements made of high-strength silicon nitride Si3N4 or Si3N4-HIP. Both ceramics deliver a longer lifespan due to a high surface quality and a low coefficient of friction. With low levels of lubrication or dry running, these extremely hard ceramics will prevent seizes; something that can often happen with conventional steel bearings. Also compared to steel, a lower weight ceramic bearing reduces centrifugal force at higher turning speeds / loads. In addition, ceramic is a natural electrical insulator.

Gehrig® ceramic roller bearings – our advantages:

-    low weight, low density and therefore low centrifugal forces
-    high temperature resistance (from -250° to 1500°C) with low thermal expansion
-    high hardness and low abrasive wear
-    good dimensional stability and very high rigidity
-    excellent corrosion resistance
-    longer life with low levels of lubrication or dry running
-    lower operating and maintenance costs resulting in less downtime
-    no electrostatic charge and very good electrical insulation
-    no magnetism; insensitive to magnetic fields
-    no rusting, no aging and does not get brittle with age
-    good availability of raw materials (unlike some specialized stainless steels)
-    environmentally friendly production and end-of-life disposal