The full ceramic ball bearings listed below are supplied with rings and balls made from zirconium dioxide (ZrO2). These zirconia bearings are available as full complement (no cage) or with cages made from PTFE, PEEK or 316 stainless steel.
These are non magnetic, non-conductive and highly corrosion resistant to most chemicals although ZrO2 bearings are not recommended for prolonged contact with steam. Full complement bearings or those with a 316 stainless cage can be used up to 400°C while bearings with a PEEK or PTFE cage can cope with temperatures of up to 250°C. For temperatures below -70°C, PTFE or 316 stainless steel cages are preferred.
Standard radial clearance for full ceramic bearings is C0 but other clearances can be supplied to order. ZrO2 ceramic bearings are generally used for their extreme temperature capabilities, excellent corrosion resistance or non-magnetic properties. Other sizes can be supplied on request.
| XY Ceramic Property | ||||||||
|---|---|---|---|---|---|---|---|---|
| Type | Unit | Zirconium | ||||||
| XY Grade | Z-100 | Z-200 | Z-300 | ZM-100 | ZB-100 | |||
| Material | ZrO2-Y2O3 | ZrO2-Y2O3 | ZrO2-Y2O3 | ZrO2-MgO | ZrO2-Y2O3 | |||
| colour | white | white | white | yellow | blue | |||
| Density | g/cm3 | 6 | 6.03 | 6.04 | 5.62 | 6.03 | ||
| Flexural Strength | Mpa | 900 | 1050 | 1200 | 450 | 1100 | ||
| Compressive Strength | Mpa | 2100 | 2200 | 2300 | 1600 | 2300 | ||
| Modules of Elasticity | Gpa | 200 | 210 | 220 | 210 | 220 | ||
| Fracture Toughness | MPam1/2 | 6 | 7 | 8 | 5.5 | 7 | ||
| Poision's Ratio | 0.3 | 0.3 | 0.3 | 0.3 | 0.3 | |||
| Hardness HRA | HRA | 89 | 90 | 90 | 88 | 90 | ||
| Vickers Hardness | HV1 | 1250 | 1450 | 1450 | 1240 | 1450 | ||
| Thermal Expansion Coefficient | 10-6K-1 | 11 | 10 | 10 | 10 | 10 | ||
| Thermal Conductivity | W/mk | 3 | 3 | 3 | 3 | 3 | ||
| Thermal Shock Resistance | △T.℃ | 400 | 400 | 400 | 400 | |||
| Maximum Use Temperature in Oxidizing Atmosphere | ℃ | 1000 | 1000 | 1000 | 850 | 1000 | ||
| Max Use Temperature in Reducing or Inert Atmosphere | ℃ | 1000 | 1000 | 1000 | 850 | 1000 | ||
| Volume Resistivity at 20℃ | Ωcm | 10^13 | 10^12 | 10^12 | 5X10^13 | 10^12 | ||
| Dielectric Strength | kV/mm | 19 | 15 | 17 | 19 | 17 |
