Metallized Ceramic Components
95% Alumina Metallized Cylinder for Vacuum Interrupters
95% Alumina Metallized Cylinder for Vacuum Interrupters，Custom 95% alumina ceramic cylinders with Mo–Mn metallization and optional plating for vacuum interrupters and high-voltage assemblies.
Description
TecCera supplies 95% Alumina Metallized Cylinder for Vacuum Interrupters，95% alumina metallized ceramic cylinders designed for vacuum interrupters and ceramic-to-metal brazed assemblies. The ceramic cylinder provides electrical insulation and structural support, while Mo–Mn metallization on the joining surfaces enables subsequent plating and brazing to compatible metal components.
Cylinder dimensions, wall thickness, metallization areas, plating finish and dimensional tolerances can be customized according to customer drawings.
Product Overview
|
Item |
Specification |
|
Product Name |
95% Alumina Metallized Ceramic Cylinder |
|
Primary Application |
Vacuum interrupters and high-voltage assemblies |
|
Ceramic Material |
95% alumina (Al₂O₃) |
|
Base Metallization |
Molybdenum–manganese (Mo–Mn) |
|
Metallization Areas |
Ends or selected surfaces according to drawing |
|
Metallization Thickness |
15–25 μm |
|
Optional Plating |
Nickel, copper, silver or gold |
|
Plating Thickness |
8–10 μm |
|
Joining Method |
Ceramic-to-metal brazing or soldering |
|
Dimensions |
Customized according to customer drawings |
|
Surface Finish |
According to drawing and application requirements |
|
Brand |
TecCera |
Technical Specifications
|
No. |
Parameter |
Typical Value / Specification |
Unit |
|
1 |
Alumina Purity |
95 |
% |
|
2 |
Bulk Density |
≥ 3.63 |
g/cm³ |
|
3 |
Thermal Conductivity at 25°C |
22.45 |
W/m·K |
|
4 |
Coefficient of Thermal Expansion, 20–1000°C |
8.26 |
×10⁻⁶/K |
|
5 |
Flexural Strength |
≥ 340 |
MPa |
|
6 |
Dielectric Strength |
≥ 8.3 |
kV/mm |
|
7 |
Dielectric Constant at 1 MHz |
9.1 |
— |
|
8 |
Dielectric Loss at 1 MHz |
≤ 0.0004 |
— |
|
Mo–Mn Metallization Thickness |
15–25 |
μm |
|
|
10 |
Optional Plating Thickness |
8–10 |
μm |
The values shown are typical specifications. Final values depend on the ceramic grade, cylinder dimensions, metallization design and agreed test method.
Key Features
Electrical Insulation
The 95% alumina ceramic body provides reliable electrical isolation for vacuum interrupters, high-voltage switching devices and related electrical assemblies.
Metallized Joining Surfaces
Mo–Mn metallization can be applied to the cylinder ends or other specified surfaces to provide a bondable interface for plating and ceramic-to-metal brazing.
Mechanical and Dimensional Stability
The ceramic cylinder provides structural support while maintaining dimensional stability under the specified operating and assembly conditions.
Custom Geometry
Outer diameter, inner diameter, length, wall thickness, grooves, steps, flanges and metallization patterns can be manufactured according to customer drawings.
Optional Plating
Nickel, copper, silver or gold finishes can be evaluated according to the brazing alloy, joining temperature, mating metal and operating environment.
Available Joining Configurations
- Alumina ceramic + Mo–Mn metallization
- Alumina ceramic + Mo–Mn metallization + nickel plating
- Alumina ceramic + Mo–Mn metallization + copper plating
- Alumina ceramic + Mo–Mn metallization + silver plating
- Alumina ceramic + Mo–Mn metallization + gold plating
- Alumina ceramic + printed silver metallization
- Selective metallization according to customer drawings
Mo–Mn is the base metallization layer. Nickel, copper, silver and gold are optional surface finishes applied according to the required joining process.
Detailed Product Information
In a vacuum interrupter, the alumina cylinder functions as an electrically insulating envelope and as part of the ceramic-to-metal sealing structure. The metallized ends allow the ceramic cylinder to be brazed to suitable metal end components.
Alumina, Kovar, copper and other metal materials have different coefficients of thermal expansion. Therefore, the joint geometry, mating metal, brazing alloy and heating cycle must be evaluated together to control residual stress and reduce the risk of cracking.
The surface finish and dimensional tolerances should be specified according to the electrical, mechanical and assembly requirements. Precision grinding can be evaluated where tighter tolerances or controlled sealing surfaces are required.
Hermeticity is a performance characteristic of the completed brazed assembly rather than the bare ceramic cylinder. When helium leak testing is required, the assembly condition, test method and acceptance criterion must be agreed separately.
Typical Applications
- Vacuum interrupters
- Vacuum contactors
- Medium- and high-voltage switchgear
- Ceramic-to-metal sealed electrical assemblies
- High-voltage insulating components
- Vacuum switching devices
- Electrical feedthrough assemblies
- RF and power tube components
- Custom vacuum electronic assemblies
Customization Requirements
Please provide the following information for quotation:
- 2D drawing or STEP/IGES file
- Outer diameter, inner diameter and length
- Wall thickness and dimensional tolerances
- Alumina purity
- Metallization position and coverage
- Metallization and plating thickness
- Required plating material
- Mating metal material
- Brazing alloy and brazing temperature
- Operating voltage and temperature
- Vacuum or leak-rate requirements
- Required quantity
- Inspection and documentation requirements
Frequently Asked Questions
Why is Mo–Mn metallization used on alumina cylinders?
Mo–Mn metallization creates a bondable surface on alumina ceramic. After suitable plating, the metallized surface can be joined to compatible metal components through brazing or soldering.
Is nickel plating required?
Nickel plating is commonly used over Mo–Mn metallization for many brazing applications, but it is not universally required. The correct finish depends on the brazing alloy, mating metal, process atmosphere and operating conditions.
Can the cylinder dimensions be customized?
Yes. Outer diameter, inner diameter, length, wall thickness, steps, grooves and metallization areas can be produced according to customer drawings, subject to manufacturing review.
Does the ceramic cylinder meet a specified helium leak rate?
The bare ceramic cylinder does not independently determine the final leak rate. Hermeticity depends on the completed ceramic-to-metal assembly, including the joint design, mating metal, brazing alloy and assembly process.
Is 99% alumina also available?
Higher-purity alumina options can be evaluated separately. Their mechanical, thermal and electrical specifications should not automatically use the same values listed for the 95% alumina version.
Request a Quote
Send TecCera your drawing, metallization pattern, plating requirement, mating metal information and required quantity. We will review the ceramic geometry and joining requirements before providing a quotation.
Technical Resources
Download the TecCera brochure for metallized alumina components, ceramic-to-metal brazed assemblies, hermetic seals, and vacuum feedthrough solutions.
Download Metallized Ceramics Brochure (PDF)How to Get a Quote
Send us your drawing or technical requirements. We will review the material, dimensions, tolerances and application conditions before quotation.
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