Al2O3 Alumina Ceramic Parts
99% and 95% Al2O3 Alumina Ceramic Rings
Wear rings and insulating collars machined to your drawing
Alumina ceramic rings replace metal collars, bushings and spacers in places where a steel part wears out, corrodes or shorts to ground. The ring is pressed and sintered from aluminium oxide, then ground to your bore, outside diameter and face flatness. Both 99% and 95% Al2O3 bodies are available, so you can trade a little dielectric performance for lower cost where the duty allows.
Key Benefits
- Rockwell hardness of at least 92 HRA keeps the bore round under abrasive slurry and dry running
- Survives continuous service to 1600 degrees C, so the ring does not creep or anneal near a burner or heater
- An insulator and a structural part at the same time, which removes the separate bushing plus washer stack
- Chemically inert against most acids and alkalis, so no galvanic pair forms with the shaft it carries
- Bore, OD, length and chamfers are all made to drawing, not picked from a catalogue of stock sizes
Problems It Solves
- Metal wear rings that pick up scoring after a few hundred hours in abrasive media
- Insulating collars that soften or carbonise where they sit next to a heating element
- Corrosion at the ring and shaft interface in pumps handling aggressive fluids
Who It Is For
- Pump and valve builders replacing metal wear parts that do not last a maintenance interval
- Heating equipment makers who need one part to insulate and to locate
- Machine builders sourcing to a drawing rather than to a stock size list
Application Scenarios
Guide and wear rings inside pump and valve assemblies
Insulating collars around electrodes and heater terminals
Spacers and standoffs inside vacuum and furnace fixtures
Seats and bushings on automotive and sensor sub-assemblies
Technical Features
- Density 3.10-3.15 g/cm3 in the ring body as supplied
- Modulus of elasticity quoted at 410 MPa on the source specification
- Maximum use temperature 1600 degrees C
- Available in both 99% and 95% alumina compositions
Manufacturing Process
Raw material preparation, forming, surface grinding, internal and external diameter grinding and precision CNC machining are all carried out in house.
Materials
- Alumina ceramic, 99% or 95% Al2O3
Specifications
| Material | Alumina ceramic, 99% or 95% Al2O3 |
|---|---|
| Shape | Ring |
| Size | Customized to drawing |
| Density | 3.10-3.15 g/cm3 |
| Rockwell hardness | 92 HRA or higher |
| Modulus of elasticity | 410 MPa |
| Maximum use temperature | 1600 degrees C |
Figures are taken from the published product specification. Values not listed are marked TBC and confirmed against your drawing before quotation.
Quality Control
- Bore and outside diameter checked against the drawing before packing
- Inspection report issued to your drawing on request
- Packing and loading photographed and sent before the shipment leaves
Certifications
No third party certification documents are published for this product. Every shipment is inspected to your drawing with an inspection report issued. Certification status is TBC and confirmed on request.
Customization Options
- Send a 2D or 3D drawing with bore, OD, length and tolerance called out
- Choose 99% or 95% alumina depending on dielectric and cost targets
- Chamfers, grooves, slots and cross holes can be ground into the ring
Comparison With Other Ceramics
Against 95% alumina, the 99% body gives higher purity and better dielectric behaviour and is the usual choice next to electrodes. Against zirconia, alumina is lighter and cheaper but less tough, so for rings that take impact or a press fit on a steel shaft, ask about a zirconia version instead.
Use Guide
- Do not press a ceramic ring onto an interference fit without a shrink or adhesive method agreed first
- Support the ring on its face rather than its edge when clamping
- State whether the bore or the OD is the datum so grinding is referenced correctly
Industries Using This Part
Related Solutions
99% 95% Al2O3 Alumina Ceramic Ring FAQ
Can you make rings to my drawing instead of a standard size?
Yes. Size is customized. Send the drawing with the bore, outside diameter, length and the tolerances you need.
Should I specify 99% or 95% alumina?
Both are available. 99% is the higher purity body with better dielectric behaviour; 95% is the usual choice when the duty is mechanical and cost matters more.
What temperature can the ring run at?
The maximum use temperature is 1600 degrees C.
What is the lead time?
Samples are delivered in 4 to 7 working days. Production is 15 to 30 days when the goods are not in stock, depending on dimension and quantity.
Do you provide samples?
Samples are offered free of charge. Freight is not covered.
What are the payment terms?
For orders up to 1000 USD, 100% in advance. For orders of 1000 USD and above, 50% T/T in advance with the balance before shipment.
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Send a 2D or 3D drawing with the critical dimensions marked. Samples are free of charge and delivered in 4 to 7 working days.
Send a 2D or 3D drawing by WhatsApp or email. Samples in 4 to 7 working days.