NITRON from Blasch, 70% silicon carbide bonded by silicon nitride, for cyclone linings, nozzles, heater tubes and large wear shapes.
Large cyclone cones, spray nozzles and heater tubes that wear, get hot and cool down again.
NITRON is cast for that combination.
Nitride bonded silicon carbide is silicon carbide whose grains are held together by silicon nitride, which gives it good erosion and corrosion resistance, high thermal conductivity and a thermal shock tolerance that dense ceramics lack. Blasch NITRON contains 70% SiC, 21% Si3N4 and 8.5% silicon oxynitride, has 16% apparent porosity and a modulus of rupture of 6,000 psi. It is used for cyclone and hydrocyclone liners, spray nozzles, immersion heater tubes and large wear shapes that would spall in a denser ceramic.
Silicon carbide grains do not bond to each other on their own. In nitride bonded silicon carbide, the bond forms during firing in nitrogen: silicon in the mix reacts to silicon nitride, which grows between the SiC grains and locks them together.
Because the bond forms in place, the part shrinks very little during firing. That is why nitride bonded silicon carbide suits large shapes and tight tolerances, and why NITRON parts come out of the Blasch process with uniform properties throughout the part.
NITRON is the Blasch grade. It is cast net shape, from small nozzles to large linings for cyclones and quench vessels. How the Blasch process works
Values from the Blasch NITRON product information sheet.
| Property | NITRON |
|---|---|
| Composition | 70% SiC, 21% Si3N4, 8.5% Si2N2O |
| Apparent porosity | 16% |
| Modulus of rupture | 6,000 psi |
| Thermal conductivity | 115 BTU·in/hr·ft²·°F |
| Coefficient of reversible thermal expansion | 2.6 x 10⁻⁶ in/in·°F |
What these numbers mean in service: the high thermal conductivity and low expansion keep temperature differences inside the part small, so NITRON resists cracking and spalling under rapid temperature change. The open porosity is part of that: it lets the structure absorb stress that would crack a fully dense body.
Compared with steel and rubber: in abrasive slurry and pneumatic service, NITRON reduces spalling and erosion and lasts much longer than steel or rubber linings. For the heaviest impact abrasion, the denser reaction bonded silicon carbide is the next step up.
In a real plant the part that wears also heats, cools and gets knocked, and nitride bonded silicon carbide is chosen because it takes all three without spalling.
From small nozzles to large linings, each part designed for its duty.
Cones, apexes and inlet scrolls in one piece, for slurry and dust.
Spray nozzles for scrubbers that resist erosion and do not clog.
Heater sheaths for molten aluminum and zinc with good heat transfer.
Large NITRON shapes for blast shrouds, quench vessels and impingement blocks.
NITRON is also used for abrasion resistant valves, in line chokes and reducers, rotary degassers and porous plugs and dust collector components, and as one of the liner grades in CeraLine lined pipe and elbows. In copper and aluminum alloys it combines non wetting with thermal shock resistance.
NITRON parts work in mining, power generation and molten metals. Blasch also makes an oxynitride bonded silicon carbide, OxyNitron, and for molten aluminum the non wetting oxide bonded grades.
NITRON values and uses: Blasch NITRON product information sheet; Blasch heavy industry and nonferrous presentations. Nitride bonding of silicon carbide: W. D. Kingery, H. K. Bowen, D. R. Uhlmann, Introduction to Ceramics, 2nd ed., Wiley, 1976.
No. It is mostly silicon carbide; silicon nitride is only the bond. Pure silicon nitride is a different, fully dense ceramic.
Reaction bonded is denser and resists heavy abrasion better. Nitride bonded tolerates thermal shock better and is the economical choice for large shapes.
Nitride bonded silicon carbide is a refractory grade used in hot service and molten metal. Ask a Blasch engineer for the limit in your atmosphere and load.
No. NITRON is a solid cast part; its wear resistance comes from the material itself, not from a surface layer.
Send the dimensions, the medium and the temperature range. A Blasch engineer checks whether NITRON or another grade fits best.
