SINTRON silicon nitride from Blasch for molten metal, wear and parts that have to pass heat through their wall.
A dense, tough ceramic that conducts heat and does not wet in nonferrous melts.
Cast to shape, without the tooling charges of pressed parts.
Silicon nitride ceramic (Si3N4) is the best choice where a part needs high strength and fracture toughness together with thermal shock resistance, for example a heater tube, a thermocouple sheath or a riser tube in molten aluminum. It does not wet in nonferrous melts and conducts heat well enough to pass heat through its wall. Blasch SINTRON silicon nitride has a flexural strength of 830 MPa and a fracture toughness of 6.1 MPa·m½, and is rated for 1,000 °C without load.
Silicon nitride is a compound of silicon and nitrogen. Its elongated grains interlock like fibers, which gives it more toughness than most other technical ceramics and lets it take thermal shock that would crack a dense alumina part.
There are several ways to make it: reaction bonded, hot pressed, sintered and sintered reaction bonded silicon nitride. They differ in density and strength, and in how complex a shape can be.
SINTRON is the Blasch silicon nitride. It is fully dense and can be formed into relatively complex shapes with good tolerance control, without the hard tooling setup charges that pressed parts carry.
Values from the Blasch SINTRON product information sheet.
| Property | SI/metric | Imperial |
|---|---|---|
| Density | 3.29 g/cm³ | 205.4 lb/ft³ |
| Porosity | 0% | 0% |
| Color | black | |
| Flexural strength | 830 MPa | 120,400 psi |
| Hardness | 1,580 kg/mm² | |
| Fracture toughness KIC | 6.1 MPa·m½ | |
| Poisson's ratio | 0.27 | 0.27 |
| Maximum use temperature, no load | 1,000 °C | 1,830 °F |
| Thermal conductivity | 30 W/m·K | 208 BTU·in/ft²·hr·°F |
| Coefficient of thermal expansion | 3.3 x 10⁻⁶ /°C | 1.8 x 10⁻⁶ /°F |
The low thermal expansion and the thermal conductivity together explain its thermal shock behavior: the part heats more evenly and grows less, so less stress builds up between its hot and cold side.
Silicon nitride is the ceramic you choose when a part has to be thin, conduct heat and still take a knock when the crew changes it out on a hot furnace.
Molten aluminum and other nonferrous alloys: SINTRON is nonwetting to molten nonferrous alloys. Heater tubes and thermocouple sheaths stay free of buildup longer, and the reading or the heat transfer stays stable.
Thin walls that must transfer heat: immersion heater tubes protect the element or burner while passing its heat into the melt. A thin, strong, conductive wall does that job better than a thick refractory tube.
Wear with impact: in valves and wear components, the toughness of silicon nitride helps where a harder but more brittle ceramic would chip.
Where it is not the first choice: Blasch rates SINTRON for 1,000 °C without load, so very hot structural parts belong in sintered silicon carbide or an oxide refractory. For large wear shapes where cost per pound matters, a bonded silicon carbide grade is usually the economical answer.
Parts for molten metal handling and wear.
Heater sheaths for aluminum and zinc that transfer heat and resist dross buildup.
Sheaths that give fast, stable readings in molten metal and hot gas.
For the same aluminum applications, Blasch also offers non wetting oxide bonded silicon carbide and aluminum titanate. Most silicon nitride parts go to molten metal plants and to chemical processing.
SINTRON values: Blasch SINTRON silicon nitride product information sheet. Product use: Blasch immersion heater tube and riser tube product pages. Types and microstructure of silicon nitride: W. D. Kingery, H. K. Bowen, D. R. Uhlmann, Introduction to Ceramics, 2nd ed., Wiley, 1976.
Yes. Silicon nitride is a non oxide technical ceramic, known for combining strength, toughness and thermal shock resistance.
It costs more than bonded silicon carbide or oxide refractories, and the Blasch grade is rated for 1,000 °C without load, lower than some silicon carbides.
No. Silicon carbide is harder; silicon nitride is tougher.
Heater tubes, thermocouple sheaths and riser tubes, because it does not wet in the melt and handles thermal shock.
Send the dimensions, the melt or medium and the temperature. A Blasch engineer checks whether silicon nitride or another grade fits better.
