Silicon Carbide (SiC) can be found both naturally as moissanite, as well as manufactured commercially to be used as an abrasive material. Individual grains can even be fused together through sintering processes to form hard ceramic materials with unrivaled hardness.
Silicon carbide ceramic is ideal for high temperature applications due to its nonoxide composition and strong chemical resistance against acids and lyes. As its strength remains consistent at up to 1400degC, silicon carbide boasts reliable performance.
Hardness
Silicon is hard compared to most metals, yet not as resilient as materials such as diamond. This is likely due to having only two valence electrons and a tetrahedral crystal lattice structure compared to four in diamond’s cubic structure; therefore making silicon more brittle but still being capable of withstanding shearing forces reasonably well.
Silicon carbide, on the other hand, is much tougher than silicon. Its crystalline structure features bonds between carbon atoms and silicon atoms to produce exceptional hardness, mechanical strength, low density, elastic modulus and thermal shock resistance – properties which enable it to resist penetration by bullets or other dangerous objects.
Silicon carbide does not exist naturally as its pure form; however, small quantities are found in meteorites as the mineral moissanite. Silicon carbide can also be synthesized using silica powder and carbon in a furnace; its resultant ceramic compound finds multiple applications within industry.
Mohs hardness scale measures the hardness of silicon carbide, ranking it third after diamond and boron carbide. Due to its ability to withstand shear and impact stresses, silicon carbide makes for an excellent material in protective coatings, cutting tools and other devices subjected to stress. Furthermore, its structural integrity prevents deformation under pressure as well as being resistant to extremely high temperatures.
Thermal Expansion Coefficient
Silicon carbide is an inert material that doesn’t react with many common chemicals, making it an excellent choice for harsh environments prone to chemical corrosion in less robust materials. Furthermore, silicon carbide’s mechanical strength and resistance against high pressure environments makes it suitable for many demanding situations.
Mohs hardness of 13 marks it as one of the hardest compounds on Earth and makes it ideal for use as tools and cutting plates, thanks to its resilience against wear and abrasion. Furthermore, its wear resistance makes it suitable for heavy applications with lots of friction such as manufacturing environments.
SiC is distinguished by a strong crystal structure comprised of tetrahedral carbon and silicon atoms, which makes its composition highly resistant to wear from other soft metals like aluminum and titanium tetrahedrons. Furthermore, SiC resists attack from acids like phosphoric, sulphuric, hydrochloric acids as well as sodium and potassium-containing salt solutions without being affected.
Silicon carbide’s superior durability and chemical inertness enable it to withstand corrosion, wear, impact damage, and other threats; hence its use as protective coatings and bulletproof armor. Furthermore, its hardness properties also make silicon carbide an excellent material choice for industrial applications that demand an exceptionally resilient ceramic material.
Chemical Corrosion Resistance
Silicon carbide is inert towards most organic and inorganic compounds.
Chemical corrosion resistance makes ceramic an invaluable material in environments exposed to highly aggressive substances, including those with intense abrasion or pumping action that could otherwise lead to their failure. It makes ceramic an especially good option when dealing with heavy loads such as heavy abrasion or pumping action that might otherwise render other ceramics obsolete.
Corrosion of SiC occurs via chemical reaction at its surface. The rate of corrosion depends on material properties such as its roughness, pore structure and composition; environmental conditions (temperature and pH); as well as individual user experiences.
Silicon carbide’s atomic structure allows it to form a protective oxide layer that blocks further chemical reactions, and its ceramic form consists of close-packed crystals with two primary coordination tetrahedra made up of four silicon and four carbon atoms bonded in an interlocked pattern, and further stacked together to form polytype structures or polar structures.
Silicon carbide boasts outstanding chemical corrosion resistance due to its polar structures, making it suitable for industrial and coated abrasives as well as refractory products and mechanical seals. Human exposure to carborundum abrasives may cause fibrotic lung disease; nonetheless, the use of these materials remains controversial and should be monitored.
Wear Resistance
Silicon carbide is one of the hardest materials in existence, second only to diamond and boron nitride. Due to its strength and durability, silicon carbide makes an excellent choice for applications requiring toughness such as cutting tools, drill bits, turbine blades and glow plugs. It boasts exceptional mechanical properties including 6.8 MPa m0.5 fracture toughness; Young’s modulus of 440 GPa; and 490 MPa flexural strength – three exceptional metrics of which silicon carbide excels.
JUNTY utilizes two main types of SiC: Reaction Bonded and Sintered, both offering excellent wear resistance. Reaction Bonded SiC is used to improve thermosetting polymers such as epoxy while Sintered SiC is employed for hardwearing components manufacturing.
Centrifugal mixing allows us to disperse ceramic particles within polymer and increase wear resistance. Three variables influence ceramic particle distribution in polymers – rotational speed, ceramic percentage and size of ceramic particles. We have discovered that optimal conditions for fabricating composites with good wear properties involve low rotational speed (30wt%) ceramic content and micro or ultrafine ceramic particle sizes of micro/ultrafine size ceramic particles.
Nitride-bonded silicon carbide showed significantly less wear in light soil compared to steel and F-61 padding weld, but higher wear in medium soil. Nitride-bonded SiC had lower wear rates in heavy soil conditions indicating its formation of a wear protective tribofilm that lowers friction coefficient and prevents mass loss.