Alumina Seal Ceramic Rings / Industry Insulation Rings
1. Description:
Energy-saving advantages of alumina ceramics on heating components
Positive Temperature Coefficient (hereinafter referred to as:PTC)is
a kind of semiconductor thermal ceramics. Its characteristic is
sensitive to temperature. It shows negative resistance when it is
lower than the Curie temperature; when it reaches the Curie
temperature, its resistance value begins to increase sharply. When
used as a heating material, it has the following superior
characteristics: automatic constant temperature, no oxygen
consumption, corrosion resistance, etc. PTC ceramics are mainly
doped barium titanate semiconductor ceramics, which have relatively
small ionization energy and can be thermally excited to generate
conductive carriers at room temperature, thereby forming
semiconductors.
2. Feature Advantages:
1) Refractory, High Temperature Resistance, Maximum Used
Temperature: 1800 ºC (3272ºF)
2) Hardness Strength, Wear Resistance Up To Mohz 9.0 ; HRA 80-90
3) High Voltage, Good Insulation Performance ,Electrical
Resistivity Up To 10∧14 Ohm.Cm
4) High Polished Surface Up To Rz0.8(Ra0.1)
5) Superior Mechanical Strength, MAX 10 MPa.m1/2 Fracture toughness
6) Pressure Resistance, Max 2300MPa compressive strength
7) Anti-High Corrosion Resistance, Such As Acid Alkali Resistance
8) Long Service Life
9) Other excellent property
3. Material Features / Properties:
| Composite | (wt %) | 99% | 99.5% | 99.8% |
| Color | | White or Ivory | White or Ivory | White or Ivory |
| Density | g/cm 3 | 3.82 | 3.9 | 3.92 |
| Hardness | HRA | 83 | 85 | 85 |
| Flexural Strength | Mpa (psi*10 3 ) | 375 | 386 | 381 |
4. Technical Parameters:
| Technical Parameters of Ceramics |
| Items | Test Conditions | Unit or Symbol | 99% AL2O3 | 95% AL2O3 | 90% AL2O3 | Zirconia | Steatite | Silicon Carbide |
| Volume Density | -- | g/cm3 | ≥3.70 | ≥3.62 | ≥3.40 | ≥5.90 | ≥2.60 | ≥3.08 |
| Tightness | -- | Pa·m³/s | ≤1.0×10-11 | ≤1.0×10-11 | ≤1.0×10-11 | - | - | - |
| Liquid Permeability | -- | -- | Pass | Pass | Pass | | Pass | - |
| Flexural Strength | - | MPa | ≥300 | ≥280 | ≥230 | ≥1100 | ≥120 | ≥400 |
| Elastic Modulus | - | GPa | - | ≥280 | ≥250 | ≥220 | - | 400 |
| Poisson Ratio | - | - | - | 0.20～0.25 | 0.20～0.25 | - | - | - |
| Thermal Shock Resistance | 800℃( Room Temperature) Cycle: 10 times | | Pass | Pass | Pass | - | - | - |
| Coefficient of Linear Expansion | 20℃～100℃ | ×10-6 K-1 | - | - | - | | ≤8 | - |
| 20℃～500℃ | ×10-6 K-1 | 6.5～7.5 | 6.5～7.5 | 6.5～7.5 | 6.5～11.2 | - | - |
| 20℃～800℃ | ×10-6 K-1 | 6.5～8.0 | 6.5～8.0 | 6.3～7.3 | | - | 4 |
| 20℃～1200℃ | ×10-6 K-1 | - | 7.0～8.5 | - | - | - | - |
| Coefficient of Thermal Conductivity | 20℃ | W/(m·k) | - | - | - | - | - | 90～110 |
| 1000℃ |
| Dielectric Constant | 1MHz 20℃ | - | 9.0～10.5 | 9.0～10 | 9.0～10 | - | ≤7.5 | - |
| 1MHz 50℃ | - | - | 9.0～10 | - | - | - | - |
| 10GHz 20℃ | - | 9.0～10.5 | 9.0～10 | 9.0～10 | - | - | - |
| Volume Resistivity | 100℃ | Ω·cm | ≥1.0×1013 | ≥1.0×1013 | ≥1.0×1013 | - | ≥1.0×1012 | - |
| 300℃ | ≥1.0×1013 | ≥1.0×1010 | ≥1.0×1013 | - | - | - |
| 500℃ | ≥1.0×109 | ≥1.0×108 | -- | - | - | - |
| Disruptive Strength | D.C | kV/mm | ≥17 | ≥15 | ≥15 | - | ≥20 | - |
| Chemical Durability | 1:9HCl | mg/c㎡ | ≤0.7 | ≤7.0 | - | - | - | - |
| 10%NaOH | mg/c㎡ | ≤0.1 | ≤0.2 | - | -- | - | - |
| Grain Size | - | μm | - | 3~12 | - | - | - | - |
5. Process Flows:
Formulating --- Granulating --- Forming --- Sintering --- Grinding
--- Printing --- Nickel Plating --- Assembing --- Brazing ---
Inspecting --- Packing
6. Production Facilities: Prilling Tower , Forming Machine , High
Temperature Sintering Kiln
7. Detection Devices:
Electric Performance Tester , Film Thickness Analyzer ,
Granulometer , Helium Mass Spectrometer Leak Detector , Universal
Pull Force Meter
8. Our advantages: Quality Assurance ; Price Competitive ; Factory Supply Directly ;
Good Service
9. Shipping and Package:
10. Our aimed market:
Notes:Above information only for reference and please contact with
us for more details freely when you have any inquiry!
