Al₂O₃ ceramic balls
Why are Al₂O₃ ceramic balls suited to pumps? High hardness, chemical inertness and long service life for industrial applications.
Material comparison · Ceramic balls
In practical use, the material properties of aluminium oxide directly affect the function of technical systems. Al₂O₃ ceramic balls are used wherever components are permanently exposed to high mechanical, chemical or thermal loads and must reliably retain their function.
Al₂O₃ compared with Si₃N₄ and ZrO₂
| Property | Si₃N₄ (silicon nitride) | Al₂O₃ (alumina) | ZrO₂ (yttria-stabilised) |
|---|---|---|---|
| Density | 3.2–3.3 g/cm³ | 3.6–3.9 g/cm³ | 6.0–6.1 g/cm³ |
| Hardness (Vickers) | 15–16 GPa | 12–18 GPa | 12–16 GPa |
| Fracture toughness | 6–8 MPa√m | 4–5 MPa√m | 7–13 MPa√m |
| Wear resistance | very good to excellent | good to very good | good to very good |
| Resistance to impact loads | good | rather low | very good |
| Risk of chipping under impact | lower | comparatively higher | lower |
| Thermal conductivity at room temperature | approx. 15–35 W/(m·K) | approx. 20–35 W/(m·K) | approx. 2–3 W/(m·K) |
| Thermal insulation | low to medium | low to medium | high |
| Maximum service temperature in air | approx. 1,000–1,400 °C | approx. 1,400–1,700 °C | approx. 800–1,000 °C (Y-TZP) |
| Thermal shock resistance | very good | medium | rather limited |
| Resistance to acids | very good against many acids; depends on grade and microstructure | very good against many acids; sensitive to hydrofluoric acid (HF) | very good against many acids; HF can attack |
| Resistance to alkalis | good to very good, depending on temperature and composition | good, but hot or concentrated alkalis can attack | good to very good, depending on medium and temperature |
| Resistance to water / steam | good under many conditions; hydrothermal attack on grain-boundary phases possible | good under usual conditions; limited hydrothermally at high temperatures | good under usual conditions; Y-TZP can age under prolonged hot water or steam exposure |
| Typical advantages | combination of hardness, toughness and thermal shock resistance | high hardness, temperature resistance and economy | high fracture toughness, impact resistance and low thermal conductivity |
Chemical resistance is a general qualitative classification. It depends strongly on concentration, temperature, exposure time and the specific ceramic grade; all three materials react differently to particular acids and alkalis.
Al₂O₃ ceramic balls are the cost-efficient standard solution for pump applications with abrasive or hot media. Silicon nitride is suited to extreme high-load applications, while zirconium oxide offers advantages in shock absorption and noise reduction.
MG technical ceramics GmbH & Co. KG supports you in selecting and designing the optimal ceramic solution. Make use of expert advice to keep your pumps running reliably and economically over the long term.
All ceramic balls
Si₃N₄, Al₂O₃ and ZrO₂ with their properties and typical applications are on the product page Ceramic balls.
Grinding & polishing
How ceramic balls are used in vibratory finishing and in barrel or centrifugal machines is covered in Ceramic balls for grinding and polishing.
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