COMPONENTS FOR MOLTEN METAL METERING SYSTEMS
Precise dosing of liquid aluminum is a critical success factor in modern aluminum casting. EKatherm® silicon nitride casting nozzles and plugs are extremely wear resistant and ensure uniform casting weights over very long periods. Coating or reworking of the functional surfaces is not necessary, and maintenance work is much lower.
EKatherm® silicon nitride components for liquid metal dosing systems are extremely reliable with the best price/performance available on the market.
| 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] | 14 |
| Knoop hardness | DIN EN 843-4 | HK 0.1 [GPa] | 13.5 |
| 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 | σD [MPa] | >2500 | |
| Poisson ratio | ν | 0.25 | |
| Fracture toughness (SENB) | Klc [MPa·m0,5] | 7 | |
| Coefficient of thermal expansion | DIN EN 821-1 | ||
| 20°C - 500°C | α [10-6/K] | 2.0 | |
| 500°C - 1000°C | α [10-6/K] | 4.0 | |
| Specific heat at 20°C | DIN EN 821-3 | cp [J/g K] | 0.7 |
| Thermal conductivity at 20°C | DIN EN 821-2 | λ [W/m K] | 25 |
| Thermal stress parameters | calculated | ||
| R1 = σB·(1-ν) / (α·E) | [K] | 875 | |
| R2 = R1·λ | [W/mm] | 22 | |
| Specific electrical resistance at 20°C |
ρ [Ω cm] | >1011 | |
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