Silicon carbide ceramic (SiC) is an engineering material with superior corrosion and thermal shock resistance, making it an attractive option for applications in national defense, aviation, aerospace and space technology, paper manufacturing and energy production.
Moissanite occurs naturally as an extremely rare mineral, while synthetic versions have been manufactured since the late 19th century for use as an abrasive. Furthermore, sintered components made with moissanite can form tough and durable ceramic components.
Hardness
Silicon carbide is one of the hardest materials, second only to diamond. Composed of carbon and silicon atoms bonded together tightly into crystal structures, silicon carbide has strong thermal and chemical stability as it resists high temperatures without losing strength, corrosion attacks from acids or alkalis and even corrosion itself.
SiC’s hardness can vary depending on a variety of factors, including its crystal structure and purity levels. A hexagonal crystal structure tends to be denser than cubic SiC due to tighter bonding patterns that contribute to its hardness. Purity levels also play a part in this regard, with higher purity levels correlating with increased hardness levels. Sintering degrees also play a factor; higher sintering degrees lead to denser material with stronger atomic bonding properties which increase its hardness.
Saint-Gobain offers an expansive portfolio of industry-recognized products that take advantage of silicon carbide ceramic’s hardness and other unique properties, including cutting tools, grinding wheels and polishing solutions. Our offerings span from abrasive tools and cutting to grinding and polishing products.
Silicon carbide (also referred to as carborundum or black silicon carbide) is an engineering ceramic with excellent thermal conductivity, oxidation resistance, wear resistance and chemical stability properties. It is often utilized in abrasive applications due to its superior wear characteristics while other notable properties include neutron irradiation resistance, heat resistance and chemical stability – these properties make silicon carbide an integral component for semiconductor electronics devices that must withstand high voltages and temperatures.
Corrosion Resistance
Silicon carbide offers exceptional corrosion resistance and can withstand temperatures of 1400 degC without losing strength, making it the go-to material for mechanical seal parts in pumps and chemical processing equipment. Furthermore, SiC ceramics have proven resilient against high process temperatures as well as complex media, such as dry/moist oxygen mixtures, acids/alkali mixtures/coal ash/slag deposits/molten salts etc. SiC ceramics are often utilized as mechanical seal parts in pumps and chemical processing equipment as well as being utilized as mechanical seal parts within these applications. In these applications they remain strong against corrosion as they retain their strength over time and have proven their strength by maintaining their strength over this range of temperature range allowing SiC ceramics ceramics their strength throughout their use despite these harsh media conditions while withstanding pressures from high processes temperatures while handling complex media conditions like dry/wet oxygen mixtures/corrosive acids/alkali mixtures/coal ash deposits/molten salts etc. SiC ceramics have demonstrated their resilience when faced with high process temperatures & complex media including dry/wet oxygen mixtures/corrosive acids/alkali mixtures/coal ash/slag deposits/molten salts etc.
However, it’s essential to recognize that silicon carbide’s corrosion resistance does not depend solely on its physical makeup; rather it comes from its oxide coating on its surface. Therefore, sintered silicon carbide and other fine ceramics can improve their corrosion resistance through specially prepared oxide coatings applied directly onto their surfaces.
Due to their unique physical, thermal, and electrical properties, technical ceramics have become indispensable tools in various industrial applications. Engineers and manufacturers must carefully consider factors like cost, durability, chemical compatibility when selecting the optimal material for a particular use case; understanding alumina and silicon carbide ceramics enables them to make informed decisions that align with industry requirements.
Thermal Conductivity
Silicon carbide is a non-oxide engineering ceramic with superior heat resistance up to 1400 degC while maintaining strength, making it the go-to material for applications requiring heat dissipation in extreme temperature environments. Due to its excellent thermal conductivity and heat dissipation properties, silicon carbide makes an excellent material choice.
Aluminium oxide has become an indispensable element in industrial processes like metallurgical deoxidizers and high-temperature furnace linings, wear parts such as mechanical seals and pumps, grinding materials for cutting tools, as well as for use as cutting abrasives.
Material’s unique chemical composition renders it extremely resistant to acids and lyes, making it the perfect material for manufacturing abrasive grits. Furthermore, its inherent toughness and hardness allow it to withstand high levels of friction in applications like metal cutting and grinding processes.
Silicon Carbide stands in third place for hardness only after cubic boron nitride and tungsten carbide in terms of hardness. As such, this remarkable material makes an excellent choice for high performance applications where weight saving considerations are key – such as in aerospace. Silicon Carbide is often found as an ingredient in grinding wheels as well as refractory and ceramic products as it has excellent corrosion and wear resistance as well as low thermal expansion rates with an Young’s modulus exceeding 400GPa for excellent corrosion and wear resistance and Young’s modulus values which make it suitable for demanding applications such as aerospace environments that demand high performance solutions such as aerospace.
Electrical Properties
Silicon carbide is known for being hard, chemically inert, and boasting great electrical properties – qualities which make it one of the most advanced ceramic materials and often found in applications like abrasive tools, cutting tools and semiconductor devices. Producing black silicon carbide requires melting a mixture of silica, quartz sand and petroleum coke in a resistance furnace at high temperatures in an electric resistance furnace at resistance furnace temperatures. The final black silicon carbide produced contains 98.5 percent pure SiC crystal structure with hexagonal crystal structure. Green silicon carbide (GSC) is also produced using similar raw materials, but features less SiC content and has longer, thinner crystals. Both forms of CMC offer excellent chemical and wear resistance as well as low thermal expansion rates and possess an extremely high modulus of elasticity for use in ceramic matrix composite production.
Silicon carbide’s ability to resist physical wear makes it an excellent material choice for products such as slide bearings, mechanical seals and spray nozzles that must withstand harsh media environments. Furthermore, its chemical inertness makes it suitable for applications involving acid separation from carrier gases or condensing acid-laden vapors at high process temperatures – applications where chemical inertness plays an essential role.
Porous silicon carbide’s electrical conductivity can be modified across a wide range by altering its chemical makeup, making it suitable for self-controlled heating elements in applications like automobile rear window defrost circuits. Furthermore, its optical transparency and resistance to oxidation make it ideal for use as mirror material in astronomical telescopes.