How the Blasch silicon carbide grades differ, from oxide bonded OXYTRON to sintered ULTRON, and which one fits your wear.
Every silicon carbide part is mostly silicon carbide.
What holds the grains together decides where it lasts.
The right silicon carbide ceramic grade depends on the bond between the grains: reaction bonded and sintered silicon carbide are dense and resist the heaviest abrasion, alumina and nitride bonded grades combine good wear resistance with thermal shock tolerance at lower cost, and oxide bonded grades are chosen for molten aluminum because they do not wet. Recrystallized silicon carbide carries load at kiln temperatures. Blasch casts all seven grades net shape, so the choice follows the application, not the shapes a supplier can make.
Silicon carbide (SiC) is a compound of silicon and carbon. As a ceramic it is very hard, conducts heat well and keeps its strength at high temperature, which makes it the standard material for parts that wear in hot, abrasive or chemically aggressive service.
SiC grains do not bond to each other easily. Each grade solves that differently: with a second phase such as alumina, silicon nitride or an oxide, with metallic silicon filled into the pores, or by sintering or recrystallizing the SiC grains themselves.
That bond sets porosity, strength, erosion resistance, thermal shock behavior and the upper temperature limit. Two grades with similar SiC content can behave very differently in the same line.
Values from the Blasch product information sheets. Erosion is volume loss in the ASTM C704 abrasion test, lower is better.
| Grade | Bond | SiC | Apparent porosity | Modulus of rupture | ASTM C704 loss |
|---|---|---|---|---|---|
| InVinCer RB | reaction bonded, silicon filled | 86% | under 0.1% | 37,700 psi (RT) | 1.0 cc |
| ULTRON | sintered | n/a | under 0.1% | 480 to 600 MPa | not stated |
| ALTRON | alumina bonded | 75% | 5 to 10% | 5,600 psi (RT) | 1.5 cc |
| OXYTRON 015XDII | oxide bonded, continuous SiC phase | 64% | 14.5% | 6,261 psi (RT) | 1.8 cc |
| InVinCer Rx | recrystallized | over 99% | under 15% | 13,800 psi (RT) | 2.4 cc |
| NITRON | nitride bonded | 70% | 16% | 6,000 psi | not stated |
| OXYTRON | oxide bonded | 67% | 14% | 8,000 psi (2,000 °F) | not stated |
Read the table as a map, not a ranking. The densest grades lose the least volume in the abrasion test, but they also cost the most and are less forgiving of a part that cracks from thermal stress.
You are not choosing silicon carbide, you are choosing what holds it together, and that decides whether the part wears out, cracks or simply stays in place.
Heavy abrasion from coarse solids and slurry: InVinCer reaction bonded silicon carbide is dense and almost free of pores. Its free silicon limits it to lower temperatures than the bonded refractory grades.
Abrasion plus chemical attack, up to very high temperature: ULTRON sintered silicon carbide has no free silicon and keeps its strength to about 1,600 °C.
Erosion where dense ceramics crack: ALTRON alumina bonded silicon carbide approaches the abrasion resistance of dense advanced ceramics and keeps the thermal shock tolerance of a refractory grade.
Large shapes, wear and molten metal: NITRON nitride bonded silicon carbide is used for cyclone linings, spray nozzles, heater tubes and large wear shapes.
Molten aluminum and replacement of cast iron: OXYTRON oxide bonded silicon carbide does not wet in aluminum and weighs about one third of a cast iron part. Its newer generation, OXYTRON 015XDII, adds a continuous SiC phase for more erosion resistance.
Kiln furniture and load at temperature: InVinCer recrystallized silicon carbide is nearly pure SiC and carries load unsupported at high temperature without sagging.
If the part also sees fast temperature changes, say so early. The bond that resists abrasion best is not always the one that survives a cold start. When silicon carbide is not the answer at all, silicon nitride or zirconia may be.
The same grades go into very different parts, each designed for its line or vessel.
One piece cast liners in steel housings for pneumatic conveying and slurry.
Cones, apexes, spigots and inlet scrolls in one piece, 1 to 60 inches in diameter.
ALTRON nozzles welded into FCC air grids in place of steel nozzles.
SiClone outlets, inlets and spin vanes in OXYTRON and ALTRON instead of cast iron.
Silicon carbide parts from Blasch run in mining and mineral processing, power generation and molten metals, wherever steel, cast iron or tile wear through between two planned turnarounds.
Grade values: Blasch product information sheets for InVinCer RB, InVinCer Rx, ALTRON, NITRON, OXYTRON, OXYTRON 015XDII and ULTRON. Test method: ASTM C704, Standard Test Method for Abrasion Resistance of Refractory Materials at Room Temperature. General properties of silicon carbide: W. D. Kingery, H. K. Bowen, D. R. Uhlmann, Introduction to Ceramics, 2nd ed., Wiley, 1976.
Yes. Silicon carbide is a non oxide ceramic, made into parts by bonding SiC grains with a second phase or by sintering them directly.
It is brittle like every ceramic, dense grades cost more, and grades with free silicon or an oxide bond have a lower temperature limit than sintered SiC.
Reaction bonded is the economical choice for large wear parts at moderate temperature. Sintered is chosen for very high temperature and strong acids or bases.
Yes. Blasch can reproduce the geometry and attachment of a worn metal part in silicon carbide, from your dimensions or a sample part.
Describe the medium, the particle size, the temperature and how often the part fails today. A Blasch engineer picks the grade and designs the part.
