Silicon Carbide Powder

Silicon Carbide is an extremely hard, non-oxide ceramic material with similar strength properties to that of diamond. Additionally, SiC boasts low thermal expansion coefficient and excellent corrosion resistant and electrical properties compared to its peers.

Washington Mills offers CARBOREX(r) grains and powders in an extensive selection of sizes, chemical makeups and applications – such as abrasives, refractories, blasting agents, compounds lapping, non-slip finishes and wiresawing – that have proven popular across industries.


Silicon carbide (abbreviated SiC) is an extremely hard, synthetically produced crystalline compound of silicon and carbon. First synthesized in 1891 by American inventor Edward G. Acheson by accident when mixing clay mixture with powdered petroleum coke using an ordinary carbon arc lamp as electric lighting system in an iron bowl with an ordinary carbon arc lamp as electric light source; Acheson discovered bright green crystals known as carborundum at that time which became known as silicon carbide or silicon carbidi (Carborundum) at that time.

Boron carbide was until 1929 the hardest of the advanced ceramic materials, boasting a Mohs hardness rating of 9, approaching that of diamond. Due to its hardness and toughness it made for ideal grinding wheels and cutting tools abrasives; furthermore its resistance at elevated temperatures made it great material for use in refractories, structural ceramics or electrical applications. Furthermore, its electrical properties at elevated temperatures made boron carbide very useful material indeed!

Ceramica nonoxidea ceramic that can withstand extreme thermal and mechanical environments is used in applications as diverse as abrasives; wear-resistant parts for industrial furnaces and rocket engines (including gas filter nozzles, combustion chamber liners), ceramics, and refractories. Ceramica offers excellent chemical attack resistance as well as strength at higher temperatures with low thermal expansion rates to withstand strong shocks.

Silicon carbide powder stands out among nonoxide high-tech refractory materials as an important nonoxide material, because of its versatility. Available both as macro and micro granular forms with distinct purities; macro forms are usually made by melting raw blocks from either Green or Black types before further processing with Barmac or Raymond grinders, ultrasonic waves or sieving to yield microgranular product.

Washington Mills creates CARBOREX(r) grains and powders tailored precisely to your size, chemical makeup and shape requirements. Our CARBOREX(r) products can be used in high precision lapping and polishing operations, sawing quartz sawing quartz sawing quartz bonded coated abrasives products pressure blasting (wet or dry). Available in multiple abrasive grit sizes packaged in 5kg bags as well as larger volumes upon request.

Thermal Conductivity

Silicon carbide powder finds many industrial uses due to its combination of hardness, thermal conductivity and semi-conducting behavior. Applications include wear resistant parts that need hardness and high tensile strength as well as ceramics (such as refractories, checker bricks, muffles, kiln furniture’s and furnace skid rails) which need resistance against heat as well as chemical inertness; electrical equipment which requires thermal conductivity with low coefficient of expansion; nuclear reactor applications which need low neutron cross sections or radiation damage resistance – just to name a few of its many uses!

Silicon carbide, an inorganic nonoxide material with an approximate melting temperature of 1500 degC and an extremely difficult material to compress or form into solids, is one of the hardest and best insulators known to mankind. Featuring a diamond-like surface and denseness comparable to diamond, silicon carbide has an extremely high specific gravity which gives it great potential as an insulator material.

Silicon carbide production from raw material involves melting molten silicon reacting with carbon to form alpha SiC. The microstructure produced is an SiC matrix cermet with small isolated islands of hard silicon metal. The final product boasts one of the highest melting points among semiconductor materials – approximately 11 GPa.

SiC’s relative density increases with increasing C additive content; 5mol% C increased densification to over 80.2wt%, close to its theoretical value. TEM images of all three bodies showed no unreacted C or Si in grain boundaries or triple points, supporting our conclusion that it had dispersed through their bodies and is dissolving into them.

Temperature-dependent thermal conductivities for pristine, C-added and Si-added SiC demonstrate that thermal conduction occurs via phonons rather than electrons as predicted by Wiedemann-Franz law. Their high thermal conductivity values can be attributed to their superior crystal quality and purity as well as relative density values of 3C-SiC samples.

Corrosion Resistance

Silicon Carbide (SiC) is an inorganic material consisting of polymorphs of carbon. With unique physical traits, SiC has been in use since the late 1800s as an abrasive and has since found applications across a range of fields due to its superior performance in high temperature environments.

Corrosion resistance in complex environments is a primary consideration when designing ceramic components, especially components made with SiC. Corrosion rates in these environments range from small to high and significantly reduce lifetime due to increased surface flaws that could fail under mechanical stress. While much progress has been made in understanding the oxidation behavior of alumina, zirconia and other ceramics in simple environments, such models do not accurately describe SiC corrosion rates and failure rates.

SiC corrosion in complex environments is further compounded by its nature as a refractory material containing small proportions of graphite, an electrical conductor. Unlike other refractories, however, graphite reduces corrosion resistance of SiC in its matrix.

Research to improve the corrosion resistance of SiC has explored its combination with metals with lower melting points; copper is often chosen, since this increases thermal shock and wear resistance of SiC. To explore this further, in this study a Cu-SiC composite with 5 and 10% SiC was created using Powder Metallurgy technology using ball milling and sintered powders; scanning electron microscopy (SEM) and Energy Dispersive Analysis of X-rays (EDAX) showed uniform distribution of SiC within Cu while salt spray tests confirmed increased corrosion resistance over its predecessor.

Washington Mills offers CARBOREX(r) silicon carbide grains and powders tailored to your exact size, chemical makeup and shape specifications for lapping and polishing, sawing quartz sawblades as well as coating bonded and coated abrasives like sandpaper or blasting media. Contact us now to learn more or place an order of our black SIC product line or place one!

Chemical Resistance

Silicon carbide is an exceptional non-oxide ceramic material with multiple applications in industry. Long known for its extreme hardness, silicon carbide has long been employed in grinding wheels and cutting tools as an abrasive, but its other qualities such as temperature resistance, low expansion rates, chemical inertness, corrosion resistance and wear resistance make it invaluable in many industrial settings, from furnace refractory lining production to wear-resistant parts found on modern engines such as rocket nozzles or gas turbine blades.

Silicon Carbide is manufactured by heating quartz sand and carbon (usually petroleum coke) together at high temperatures in a resistance furnace, creating green or black-colored crystals depending on any impurities present. After cooling and densifying, these grains can then be used in densified powder form that can either be combined with metallic silica to produce dense sintered silicon carbide products, or re-crystallized for larger components.

Density and surface chemistry of Silicon carbide powder play an integral part in its resistance to corrosion from oxidizing acids such as sulphuric, nitric, and hydrochloric acids. This occurs due to a layer of SiO2 acting as an oxygen barrier which prevents direct reaction between an attacking species and substrate surface. Depending upon chemical composition of attacking species as well as reaction environment conditions, either this oxide barrier may erode away entirely or it can remain intact and replenish itself from air sources such as the atmosphere.

Corrosion resistance of materials is determined by their ability to passivate an attack by producing an oxide layer and passivating any attack, and silicon and carbon can form strong covalent bonds thanks to sharing electron pairs in sp3 hybrid orbitals, making the material resistant. Refractory and ceramic applications both benefit from coating silicon carbide with protective oxide layers for improved corrosion resistance.

Silicon carbide’s chemical inertness and other properties make it a suitable replacement for metals such as nickel, molybdenum and tungsten in abrasive machining applications, where its durability and stability make it essential. Silicon carbide also forms an integral component in modern lapidary equipment such as ring saws and lathes due to its durability and stability; additionally its extraordinary stability has found use in refractory applications like copper melting furnace lining, smelting tank liners, slag/sand casting of kiln furniture’s such as furniture’s, saggers checker bricks muffles arc and electric furnace zinc plate and crucibles.

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