What Is an Alumina Sleeve for Shaft?
An alumina sleeve for shaft is a precision ceramic protective sleeve fitted over a metal shaft to reduce wear, corrosion and seal-area damage in rotating equipment. It is commonly used in pumps, mixers, mechanical seals and bearing support areas where metal sleeves may be scored by abrasive particles, attacked by chemicals or affected by unstable running clearance.
ADCERAX can review drawing-based alumina shaft sleeves with customized inner diameter, outer diameter, length, wall thickness, chamfer, groove, shoulder and surface finish according to the operating condition.
Alumina Sleeve for Shaft Specifications
| Alumina Sleeve for Shaft | ||
| Item No. | Diameter (mm) | Thickness (mm) |
| AT-YHL-ZT001 | Customize | |
Alumina Sleeve for Shaft Properties
| Property | Unit/condition | AD-ALU-999 | AD-ALU-997 | AD-ALU-995 | AD-ALU-990 | AD-ALU-960 | AD-ALU-950 |
|---|---|---|---|---|---|---|---|
| Al₂O₃ content | wt%, nominal | 99.90 | 99.70 | 99.50 | 99.00 | 96 | 95 |
| Volume density | g/cm³ | 3.94 | 3.94 | 3.90–3.92 | 3.80–3.91 | 3.70 | 3.75 |
| Flexural strength | MPa, 20 °C | 315–340 | 330 | 320–350 | 300–320 | 300 | 280 |
| Compressive strength | MPa, 20 °C | 2558–2900 | 2500 | 2400 | 2400 | 2000 | 2000 |
| Young’s modulus | GPa | 359–375 | 370 | 365 | 355 | 275 (20 °C) | 340 |
| Fracture toughness K<sub>IC</sub> | MPa·m¹ᐟ², method-dependent | 3.8–4.2 | 3.6 | 3.5 | 3.3 | 3.5 (20 °C) | 3.0 |
| Thermal conductivity | W/(m·K) | 35–42 (25 °C) | 35–40 (25 °C) | 30–38 (25 °C) | 24 (25 °C) | 25 (20 °C) | 18–25 (25 °C) |
| Mean CTE | 10⁻⁶/K, stated range | 7.6 (25–800 °C) | 7.6 (25–800 °C) | 7.6 (25–800 °C) | 7.2 (25–800 °C) | 8.2 (25–1000 °C) | 7.6 (25–800 °C) |
| Water absorption | %, selection limit | ≤0.01 | ≤0.05 | ≤0.10 | ≤0.10 | ≈0 (typical) | ≤0.20 |
| Mohs hardness | 9 | 9 | 9 | 9 | / | 9 | |
| Vickers hardness | HV1, 1 kgf | / | / | / | / | 1600 | / |
| Use temperature guide | °C, application-dependent | 1750 | 1700 | 1650 | 1600 | 1600 max in air | 1400 |
| Color | Ivory | Ivory | Ivory | Ivory | White | Ivory / white |
Why Use an Alumina Shaft Sleeve?
1. Resist Wear at Seals and Bushings
Dense alumina provides a hard surface where sliding contact and abrasive particles can score a metal sleeve. By limiting wear, the sleeve helps keep bushing clearance closer to its design value.
2. Resist Corrosion in Water and Chemical Service
Alumina resists corrosion in many acidic, alkaline, and saline fluids. The right grade depends on the fluid, its concentration, and the operating temperature.
3. Replace the Sleeve Instead of the Shaft
The sleeve takes the wear at the contact surface. If the pump or mixer shaft remains within tolerance, you can replace the worn sleeve without remachining or replacing the shaft.
4. Fit an Existing Shaft or a New Assembly
ADCERAX machines each alumina shaft sleeve to your approved drawing for a retrofit or a new OEM assembly.
- Dimensions: Inside diameter, outside diameter, length, and wall thickness.
- Features: Chamfers, steps, grooves, and shoulders.
Common Shaft Sleeve Problems Alumina Can Help Solve
| Problem | How Alumina Sleeve Helps | Review Before Use |
|---|---|---|
| Metal sleeve scoring | A hard ceramic surface helps resist abrasive grooves caused by particles. | Confirm solids content, particle size and shaft speed. |
| Seal-area corrosion | Alumina helps reduce chemical attack in many process media. | Confirm chemical compatibility and temperature. |
| Unstable running clearance | Precision-ground ID and OD can support more predictable fit. | Confirm tolerance stack-up and shaft runout. |
| Frequent shaft repair | A replaceable sleeve can protect the main shaft from direct wear. | Confirm sleeve removal and replacement method. |
| Contamination from metal wear | Alumina can reduce metal particle generation at the contact zone. | Confirm whether ceramic particles or edge chipping would be acceptable. |
| Ceramic cracking after assembly | Proper fit, alignment and edge design reduce local stress. | Confirm interference, chamfer and pressing method. |
Alumina Ceramic Sleeve for Shaft Packaging
- Each alumina sleeve for the shaft is wrapped individually with soft cushioning material to prevent chipping during transport.
