Alumina ceramic components / relay ceramic assemblies / ceramic - metal brazed contactor
1. Description:
The present paper deals with an effective and alternative adjustment method for precise alignments of components of precision engineering and optics—the so-called method of stepped transfer of momentum bases on measured stroke impulses, which act onto a pre-stressed object and effect stepwise movements. The strokes are generated and applied to the components in several directions by special electromechanical hammers by means of a PC software and a measurement device. The automatic operation is finished if the target position of the object is attained. Achieved adjustment accuracies for the fixed components may be in the sub-micron range. The paper discusses theory and experiment of motion behavior of pushed components under the influence of applied momentum, pre-stressing and frictional forces. Additionally, it describes the wide application range of this adjustment method on the basis of developed prototypes.
2. Feature Advantages:
1) High elasticity modulus
2) High compressive strength.
3) Anti corrosion
4) Abrasion resistance
5) Impact resistance
6) High precision
7) High stability
8) Good advanced ceramic materials
9) High welding sealing performance
10) High hardness and high density
11) Low thermal conductivity
12) Chemical inertness
13) Good wear resistance
14) High Fracture toughness
15) Good insulation performance
16) High temperature resistance
17) A variety of specifications is available
18) Satisfy various technical requests
19) Lower medium spoilage
20) Stiffness texture
21) Widely apply for automotive ceramic sensor , ceramic heater ,electric heating
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 | - | ||||
