SILICON NITRIDE (Si3N4) PUMP LINERS
In the effort to develop ever faster and more energy efficient processes for melting aluminum, electromagnetic pumps play an ever more important role. These pumps permit fast and uniform mixing of the melting bath without mechanical moving parts.
The key to optimized pump operations are wear-free, low-maintenance, chemically resistant linings. EKatherm® silicon nitride pump liners provide the ideal answer to these requirements and, thanks to their low wall thicknesses, enable optimum utilization of the electromagnetic field of the pump.
EKatherm® silicon nitride is the material of choice for the cost-optimized operation of electromagnetic pumps.
| Silicon Nitride | |||
| Material properties | Norm | Symbol/Unit | EKatherm® |
| Density | DIN EN 623-2 | ρ [g/cm3] | >3.24 |
| Porosity | DIN EN 623-2 | P [%] | <0.5 |
| Mean grain size | [μm] | <2 | |
| Aspect ratio (L/D) | 3-5 | ||
| Phase composition | β-Si3N4, Oxide | ||
| Vickers hardness | DIN EN 843-4 | HV 1 [GPa] | 15 |
| Knoop hardness | DIN EN 843-4 | HK 0.1 [GPa] | 15 |
| Young's modulus | DIN EN 843-2 | E [GPa] | 300 |
| Weibull modulus | DIN EN 843-5 | m | 15 |
| Flexural strength, 4-pt bending | DIN EN 843-1 | σB [MPa] | 700 |
| Compressive strength | DIN 51104 | σD [MPa] | >2500 |
| Poisson ratio | DIN EN 843-2 | ν | 0.28 |
| Fracture toughness (SENB) | Klc [MPa·m0,5] | 7 | |
| Coefficient of thermal expansion | DIN EN 821-1 | ||
| 25°C - 500°C | α [10-6/K] | 2.5 | |
| 500°C - 1000°C | α [10-6/K] | 3.9 | |
| Specific heat at 25°C | DIN EN 821-3 | cp [J/g K] | 0.65 |
| Thermal conductivity at 25°C | DIN EN 821-2 | λ [W/m K] | 27 |
| Thermal stress parameters | calculated | ||
| R1 = σB·(1-ν) / (α·E) | [K] | 672 | |
| R2 = R1·λ | [W/mm] | 18 | |
| Specific electrical resistance at 25°C |
DIN EN 50359 | ρ [Ω cm] | >1011 |
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