Ceramic Bearing vs. Steel Bearing Material Comparison Chart
Item |
Unit |
Si3N4 |
ZrO2 |
Al2O3 (99.5%) |
SiC |
Bearing Steel |
Density |
g/cm3 |
3.23 |
6.05 |
3.92 |
3.12 |
7.85 |
Coefficient of Friction |
MPa•m1/2 |
0.0010 |
0.0012 |
|
|
|
Water Absorption |
% |
0 |
0 |
0 |
0 |
0 |
Coeffficient of Linear Thermal Expansion |
10-6/k |
3.2 |
10.5 |
8.5 |
3 |
12.5 |
Modulus of Elasticity (Young's Mod.) |
GPa |
300 |
210 |
340 |
440 |
208 |
Poisson's Ratio |
/ |
0.26 |
0.3 |
0.22 |
0.17 |
0.3 |
Hardness (Hv) |
MPa |
1500 |
1200 |
1650 |
2800 |
700 |
Flexural Strength (@ R.T.) |
MPa |
720 |
950 |
310 |
390 |
520 (tensile strength) |
Flexural Strength (700°) |
MPa |
450 |
210 |
230 |
380 |
/ |
Compressive Strength (@R.T.) |
MPa |
2300 |
2000 |
1800 |
1800 |
/ |
Fracture Toughness, Kb |
MPa*m1/2 |
6.2 |
10 |
4.2 |
3.9 |
25 |
Thermal Conductivity (@R.T.) |
W/m*k |
25 |
2 |
26 |
120 |
40 |
Electrical Resistivity (@R.T.) |
Ω*mm2/m |
>1013 |
>1015 |
>1016 |
>103 |
0.1~1 |
Max. Use Temperature (no loading) |
°F |
1050 |
750 |
1500 |
1700 |
300 |
Corrision Resistance |
/ |
Excellent |
Excellent |
Excellent |
Excellent |
Poor |