Silicon Nitride Thermocouple Protection Tubes
Silicon Nitride Ceramics Family
SKU: FWM/SN-TPT-001
- Material
- Silicon Nitride (Si₃N₄) – Gas Pressure Sintered (GPS) / High-density
- Size
- Outer diameter, bore and length to application specification
- MOQ
- 5 pieces per type
- Applications
- Aluminum Casting & Foundry
Silicon nitride thermocouple protection tubes shield temperature sensors from molten aluminium while allowing heat to reach the sensing element.
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Product Description
Silicon nitride thermocouple protection tubes shield temperature sensors from molten aluminium while allowing heat to reach the sensing element.
A closed-end ceramic sheath surrounds the thermocouple and separates it from direct contact with the melt. The tube transfers heat through its wall for temperature measurement in melting furnaces, holding furnaces and metal-transfer systems; it is not the temperature sensor itself.
Silicon nitride combines mechanical strength with resistance to thermal shock, making it useful where tubes encounter repeated temperature changes. Its low wettability by molten aluminium helps reduce adhering metal and simplifies cleaning of the exposed surface.
Product Features
- Thermal-shock resistance helps the ceramic withstand temperature changes during foundry operation
- Low wettability by molten aluminium helps reduce metal adhesion and makes cleaning easier
- Mechanical strength supports a protective sheath around the temperature-sensing element
- Heat transfer through the tube wall allows the enclosed sensor to follow melt-temperature changes
- Closed-end geometry separates the sensor from direct molten-metal contact
Typical Applications
- Temperature measurement in aluminum melting and holding furnaces
- Low-pressure die casting and continuous casting systems
- Non-ferrous metal foundries and smelters
- Launders, pouring troughs and molten metal transfer systems
- Direct and indirect temperature sensing in molten metal
Si₃N₄ (N7000) Typical Properties
| Property | N7000 | Condition / method |
|---|---|---|
| Bulk density (g/cm³) | 3.22 | — |
| Four-point bending strength (MPa) | 800 | Room temperature; four-point bending, 40/20 mm spans |
| Fracture toughness (MPa·m½) | 6.7 | — |
| Hardness (GPa) | 15 | DPH |
| Young’s modulus (GPa) | 290 | Room temperature |
| Thermal conductivity (W/(m·K)) | 20 | Room temperature |
| Coefficient of thermal expansion (10⁻⁶/K) | 3.4 | Room temperature–1000°C |
| Typical maximum material temperature (°C) | 1000 | — |
| Weibull modulus | >15 | Room temperature |
| Thermal shock coefficient R1 (K) | 620 | R1 coefficient |
Available Forms
Send drawing, dimensions, immersion length, operating temperature and quantity for feasibility review and quotation.
- Straight tubes, flanged tubes, closed-end or open-end designs
- Custom outer/inner diameter, length and wall thickness
- Optional threaded, flanged or grooved joints
Packaging & Shipping
Packing and shipment arrangements are selected for the confirmed tube geometry and order requirements.
| Item | Details |
|---|---|
| Packaging & shipping | Individually protected, cushioned and packed in export cartons or wooden cases according to size and quantity. Other commercial terms are confirmed in the quotation. |
| Payment terms | T/T / Western Union / PayPal; 50% advance payment, 50% balance before shipment |
| Shipping methods | Sea freight / Air freight / Door-to-door courier |
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