What Is Silicon Carbide?

Silicon carbide is used in electronic devices that amplify, switch or convert signals within an electrical circuit. Due to its lower voltage resistance and temperature capabilities, these devices are able to operate at higher frequencies with less power losses.

SiC is produced through an electric furnace using the Acheson process and by heating silica sand mixed with carbon typically from petroleum coke, in an electric furnace. The end product of this is small crystalline grains with green or black hues depending on purity levels.

Characteristics

Silicon carbide (sic) is a covalently bonded light grey solid material with an extremely high melting point and strong corrosion resistance, and boasts excellent thermal shock and vibration resistance as well as being stiff, strong, and dense. Its crystalline structure consists of close-packed primary coordination tetrahedra composed of four silicon atoms connected by four carbon atoms arranged hexagonally arranged within hexagonal units for easier manufacturing process; these primary coordination tetrahedra provide interesting electrical properties – such as acting as an insulator in pure form while doped with other elements can exhibit semiconductivity or conductivity when doped with other elements.

Due to its hard, abrasive nature and wear resistance properties, silicon carbide has long been used as an abrasive for grinding, sandblasting, honing and water jet cutting applications as well as in metallurgy and steel production applications since the late 19th century. Furthermore, silicon carbide plays an integral part in ceramic brake disc manufacturing for cars reducing friction and noise emissions.

Silicon carbide semiconductors boast significant advantages over silicon semiconductors in electronic applications, including 10 times greater breakdown electric field strength, significantly lower drift layer resistance per area, and greater withstand voltage tolerance (600V to thousands of V). Silicon carbide’s thin layers also enable devices to achieve smaller sizes and higher power densities – driving its adoption for use in electric vehicle power management systems, which supports increased battery drive distance.

Applications

Silicon carbide boasts excellent tribological properties, high durability, and corrosion resistance, and can operate under high temperatures without degradation or cracking. Silicon carbide finds use as part of tungsten carbide tools as well as in blasting applications as an abrasive.

Silicon carbide wafers, commonly used in electronic devices, require less power than their silicon counterparts to operate effectively at higher voltages, temperatures, frequencies and thermal conductivities; furthermore they possess greater thermal conductivity resistance and heat shock tolerance, leading to smaller passive components with reduced weight and costs overall compared to silicon based solutions. Schottky diodes and MOSFETs (in both discrete and power module packaging) are popular examples of uses for this material.

SiC is an impressive material to work with; however, its production requires an intricate process involving mixing, crushing and sintering raw materials before being transformed into dense black or gray powder that can then be cut or ground into specific sizes for various uses.

Washington Mills offers CARBOREX(r) silicon carbide in various chemistries and sizes to serve a range of industries such as abrasive blasting, ceramics insulation metallurgical refractories refractories Wire Sawing Wear-resistance. Our team of experts are here to show you all of its capabilities!

Manufacturing

Sic silicon carbide is produced through sintering of a finely ground mixture of raw materials. These raw materials may include various elements such as sand and petroleum coke or even two or more distinct materials that are mixed according to specific ratios before being placed in an electric arc furnace and heated until high temperatures. Coke or sand particles are burned off to produce carbon which then bonds together with silicon to form what we know as silicon carbide.

Crude silicon carbide is refined through sorting, milling and chemical treatments to produce finished grains and powders suitable for various uses. Black-grey silicon carbide with only diamond and cubic boron nitride being harder is commonly used to create ceramic plates used in bulletproof vests – offering reliable ballistic protection while simultaneously being significantly lighter than armoured steel or aluminium oxide options.

Pure silicon carbide is uncommon in nature and must be produced artificially through synthetic means. The Lely method involves heating a granite crucible at high temperatures to sublimate silicon carbide powder into crystals that are then deposited onto graphite substrates at lower temperatures using another process known as sublimation. When complete, crystals can then be trimmed to their desired sizes and shapes before being doped with impurities such as boron to produce P-type conductivity in SiC.

Safety

Silicon carbide’s resistance to high temperatures and radiation make it the ideal material for electronics on spacecraft operating in Venus’ scorching 460 degC surface and Jupiter’s intense atmospheric pressures. Radiation hard silicon carbide electronics will allow smaller spacecraft, more scientific instruments can be included on each mission and longer duration operations – leading to reduced size and weight while improving mission durations.

Continuous fiber-reinforced SiC matrix composites (SiCf/SiC) are promising materials for future fusion reactors’ first walls and blankets, as they possess many desirable properties including high temperature mechanical performance with superior damage tolerance to monolithic SiC [1,2], outstanding thermal conductivity and reduced activation to neutron-induced radioactivity [3-6].

Figure 9a-c shows that, according to structural analysis results presented here, both SS-310 and Zry-4 claddings exhibit similar safety margins during primary Tresca stress intervals of an LBLOCA; however, SiC is shown to offer larger margins due to its superior primary Tresca stress values and ultimate tensile strength values than Zry-4.

Figure 11 illustrates that spatial self-shielding effects vary according to cladding type, as shown by Figure 11. As can be seen for each model (SiC or SS-310), Pu-239 buildup differs during LBLOCA tests with fuel pellets from each of them, leading to greater Pu-239 concentration near their respective cladding models (SS-310 model being more likely) during MOL and EOL than SiC model.