Ceramics as a material
| Property / Material | Al₂O₃ (alumina) | ZrO₂ (zirconia) | ZTA (ZTA) | SiC (SiC) | Si₃N₄ (Si₃N₄) |
|---|---|---|---|---|---|
| Density [g/cm³] |
3,8 | 5,8 | 4,2 | 3,15 | 3,25 |
| Hardness (HV 10) [GPa] |
15 | 11,5 | 14 | 23,5 | 14,5 |
| Bending strength σ4B [MPa] |
395 | 985 | 800 | 450 | 800 |
| Compressive strength [MPa] |
2700 | 2350 | 2800 | 3250 | 3200 |
| Modulus of elasticity [GPa] |
350 | 210 | 350 | 425 | 300 |
| Fracture toughness K1C [GPa] |
3,5 | 7 | 4,2 | 3,5 | 5,5 |
| Thermal expansion [×10⁻⁶/K (20–800 °C)] |
7,6 | 10,7 | 8,4 | 4,1 | 2,9 |
| Thermal conductivity [W/m*K (20 °C)] |
24 | 2,5 | 21 | 130 | 40 |
| Max. Temp. [°C] |
1625 | 925 | 1100 | 1725 | 1375 |
Comparison Table of Key Features
The values listed are maximum values. The actual performance characteristics depend on the material and can be customized according to the industry and specific customer requirements. A detailed overview is available in the download section .
Compressive strength
- Extremely high values: Ceramics achieve compressive strengths of up to 3,900 MPa, significantly outperforming metallic materials.
- Dimensionally stable under load: Dense ceramics such as Al₂O₃, ZrO₂, SiC und Si₃N₄ remain undeformed even under extreme pressure.
- Ideal for pressure components: Particularly advantageous in ball valve seats, where high pressure loads must be absorbed continuously.
- Much greater difference compared to metals: A comparison with metallic materials impressively demonstrates the difference in compressive strength.
Bending strength
- High performance under stress: Ceramics such as zirconia (ZrO₂) and silicon nitride (Si₃N₄) offer impressively high flexural strength—ideal for components that require reliable stability under torque and shear forces.
- Perfect for dynamic applications: Materials with high flexural strength enable durable and precise components, such as ceramic balls,that retain their shape and function even under extreme operating conditions.
- Safety through material selection: The right ceramic ensures that components operate reliably even under varying loads—a clear advantage over metals, which can fatigue more quickly.
- Maximum performance in use: Thanks to their high flexural strength, premium ceramics offer an exceptional combination of precision, service life, and process reliability.
Density
- Significantly lower weight: Ceramics have a density up to 78% lower than cemented carbide and up to 60% lower than stainless steel.
- An advantage in every design: Thanks to the reduced weight, components are easier to handle, move faster, and can be driven more efficiently.
- Optimized system performance: Lower mass reduces inertia, minimizes energy requirements, and increases dynamics—ideal for moving components.
- Economic efficiency: Lightweight ceramic components simplify assembly, reduce transportation costs, and increase the overall efficiency of the system.
Hardness
- Exceptional material hardness: Ceramic materials achieve extremely high hardness values and far exceed those of metallic materials—the foundation for maximum service life.
- High abrasion resistance: The enormous surface hardness prevents material wear even during prolonged contact with hard particles, sand, or solids.
- Stable under mixed loads: Even when subjected to a combination of friction, abrasion, and impact, ceramics remain dimensionally stable and perform effectively.
- Ideal for extreme applications: Wherever metallic materials wear out or deform, ceramics remain reliably hard and durable.
Temperature stability
- High temperature stability: Ceramic components retain their shape, strength, and physical properties even at very high temperatures—a clear advantage over many metallic materials.
- Important design criterion: Unlike the maximum operating temperature, thermal shock resistance must always be considered separately, as rapid temperature changes can be more critical than high temperatures themselves.
- Material-dependent differences: Thermal shock resistance varies depending on the type of ceramic; some materials are more sensitive to rapid temperature changes than others.
- Geometry as an influencing factor: Simple geometries such as tubes are significantly less susceptible to thermal shock than components with widely varying wall thicknesses or complex shapes.
Corrosion resistance
Universal media resistance: Ceramic materials are completely resistant to most solvents and aqueous salt solutions and offer significantly greater corrosion resistance than many other materials.
- High acid resistance: Common engineering ceramics reliably withstand most acids even at elevated temperatures while retaining their physical properties.
- Material-dependent limitations: Oxide ceramics are not resistant to fluorides, and certain materials such as Y-PSZ are sensitive to water vapor (hydrothermal instability). Y-PSZ are sensitive to water vapor (hydrothermal instability).
- Consideration of media mixtures: Mixtures of reagents may behave differently than their individual components—therefore, chemical combinations must always be evaluated on a case-by-case basis.
Ceramic vs. Metal vs. Plastic – An Overview of the Benefits
| Property | Ceramics | Metal | Plastic |
|---|---|---|---|
| Hardness | Very good | Medium | Weak |
| Wear resistance | Very good | Medium | Weak |
| Chemical resistance: | Very good | Weak | Medium |
| Temperature resistance | Very good | Medium | Weak |
| Biocompatibility | Very good | Weak | Medium |
| Weight / Density | Medium | Weak | Very good |
| Electrical insulation | Very good | Weak | Medium |
Sensors & Electronics:
Insulators, substrates, piezoceramic elements
Medical Technology & Pharmaceuticals:
Implants, seals, sterile components
Food Technology:
Hygienic valves, no dead space
Pump & Valve Technology:
Wear-free seals, plain bearings
Automotive & OEM:
complex geometries, high load-bearing capacity
Consumer products:
Durable components in coffee machines, plumbing fixtures, etc.