■ Introduction:
Silicon nitride ceramic riser tube for metallurgy is an excellent combination of material properties.Silicon nitride ceramic riser are nearly as light as silicon carbide (SiC), but their microstructure gives them excellent thermal shock resistance and their high fracture toughness makes them resistant to impacts and shocks. Silicon nitride ceramic tube is formed by cold isostatic pressing (CIP) and sintered by Gas Pressure Sintering (GSPN). The life time of silicon nitride riser tube for aluminium foundry is over 10 times longer than traditional iron riser tube. So it greatly reduces the changing times of riser tube and full ensure the continuous and automatic of production. Silicon nitride riser tubes are widely used for aluminum melting and non-ferrous metal industry.
■ Technical data sheet:
Properties | Unit | Data |
Si3 N4 Content | % | ≧92% |
Density | g/cm3 | ≧3. 1 |
Relative Density | g/cm3 | >99.6 |
Elasticity Modulus | Gpa | 300-500 |
Crushing Load Ratio | (25℃)% | ≧45 |
Hardness | (Hv)Mpa | 1800-2000 |
Fracture Toughness | Mpa•m1/2 | 7.0-8.5 |
Flexural Strength | Mpa | ≧600 |
Poisson Ratio | / | 0.25 |
Coefficient of linear expansion | 10-6 K- 1 | 3.2-3.4 |
Heat Conductivity | W•(M•K)- 1 | 20-25 |
Surface smoothness | / | ≤0.3 |
Electrical isolation | KV | ≧20 |
Acid&Alkali Resistance | / | excellent |
Magnetism | / | Without |
Working Temperature | ℃ | 1400 |
■ Advantages:
1.High strength good compactness of Silicon nitride tube for metallurgy
2.Low thermal expansion coefficien of Silicon nitride riser for smelting
3. Good corrosion resistanc of Silicon nitride ceramic tube
4.Excellent thermal shock resistance of Silicon nitride ceramic riser
5.No wetting by molten aluminium &other non-ferrous molten metal