Silicon carbide is one of the hardest and lightest ceramic materials. Only small amounts are found naturally as moissanite crystals; therefore it must be synthesized.
As it is non-toxicologically safe, rubber seals make an excellent material choice for friction bearing dynamic sealing technology and mechanical seals in pumps and drive systems. Rubber is also suitable for harsh conditions in ballistics, chemical production, paper manufacturing and pipe system components – making this material highly desired by manufacturers and users alike.
Hardness
Silicon carbide, commonly referred to as “carborundum,” is an extremely hard chemical compound composed of both silicon and carbon. As a wide band-gap semiconductor with incredible durability, silicon carbide can be found naturally as the rare mineral moissanite but more commonly mass-produced in powder or crystal form for use in car brake pads or bulletproof vest ceramic plates.
Silicon carbide stands out among durable materials thanks to its combination of hardness, flexural strength, fracture toughness and wear resistance – qualities which enable it to withstand even the harshest environmental conditions. Mohs scale hardness rating of 9.5 places it among diamond and boron carbide as one of the hardest materials. As such, silicon carbide holds its shape even under intense stress exposure with incredible tensile strength to boot!
Silicon carbide ceramics’ low coefficient of friction makes them an excellent abrasive material, suitable for grinding, cutting and blasting applications in industries. Furthermore, their corrosion resistant qualities also make them useful as erosion resisting coatings on metallic surfaces.
Sintered silicon carbide (SiC) mechanical properties are greatly affected by porosity, as its presence can significantly lower their hardness and Young’s modulus. Unfortunately, data on this effect are scarce. To better understand its influence on performance, this study investigated four SiC ceramic samples with various porosities by measuring their hardness as compared to their fracture toughness to understand its impact on performance.
Thermal Conductivity
Silicon carbide stands out among engineering ceramics for its superior thermal conductivity, due to its face-centered cubic structure and low crystalline defect density of pure SiC. Furthermore, this ceramic offers good resistance against corrosion as well as being temperature stable with chemical environments.
Ceramic material that is chemically inert such as silica is one of the best options for use in harsh conditions like chemical production, papermaking and pipeline systems. Ceramic has excellent mechanical properties like high flexural strength and fracture toughness as well as an extremely high Young’s modulus that promotes excellent dimensional stability and has good resistance against erosion and abrasion; making it suitable for friction bearing dynamic seals or mechanical seals operating with water/steam as the sole lubricant.
Silicon carbide ceramics possess greater wear resistance than both alumina (Al2O3) and zirconia, and better thermal shock and fatigue properties than corundum, but still fall short of boron carbide’s exceptional performance. However, developments like yttria-stabilized zirconia could one day bridge this gap by combining all three materials’ best characteristics into one material with its improved flexural strength, fracture toughness, while still retaining thermal conductivity–making it the optimal material choice!
Resistance to Corrosion
Silicon carbide ceramics boast high modulus of elasticity and zero porosity, making them one of the most durable industrial ceramics available. They offer great protection from oxidation, chemical corrosion and thermal shock at elevated temperatures; comparable thermal shock resistance levels exist with zirconia and alumina [87-88].
Silicon Carbide Ceramics’ high tensile strength makes them resistant to fatigue. Furthermore, their hardness provides outstanding wear resistance and low frictional characteristics which makes it an excellent material choice for mechanical seals and bearings as well as semiconductor processing equipment due to their chemical stability, thermal conductivity and electrical semiconductivity – qualities which also make silicon carbide ceramics popular among machine part manufacturers and general industrial machine components manufacturers.
Reactivity of ceramic materials is heavily determined by their surface structure, such as presence of oxide impurities. Oxygen diffusion into substrate can be hindered, leading to parabolic reaction kinetics; when an attacking species dissolves in silica, however, protective oxide barriers can form between ceramic material and deposit deposits that attack it.
Silicon carbide is an integral part of ceramic glazes due to its carbon release which reduces metallic oxides like iron and copper during reduction firings (foam or crater glazing) by breaking their chemical bonds and thus helping reduce them in reduction firings (foam or crater glazing). Unfortunately, however, this process has been linked with human lung diseases when inhaled as particulate matter [89], though there has not been conclusive proof for such links yet; nonetheless it should remain of great concern when used as part of an abrasive material [89]. Although no definitive proof exists between human fibrotic lung disease and using abrasives remains of concern when using them is at issue and will continue.
Ballistic Resistance
Silicon carbide ceramic (SiC) is one of the hardest, strongest advanced ceramic materials currently available. Found naturally only in trace quantities as moissanite mineral and only available through synthetic means for manufacture, it finds many industrial uses due to its hardness, low thermal expansion coefficient and resistance to acids – including defense applications as well as in aerospace engineering technology and automobile industries.
Recently, SiC ceramics were combined with ultra-high molecular weight polyethylene (UHMWPE) fabrics with an areal density of 7.3 kg/m2. In this ballistic study, two tests of this material were compared: CA and SA tests. While CA employs multiple layers of armor plate while SA uses only a single one; in both instances an FEA software was utilized which combined solid element and smoothed surface-based physics; its model included high strain rate constitutive behavior as well as damage inducing dilation and stress triaxiality in its model.
Results revealed that increased pre-stress caused ceramic to deform more significantly and lead to larger holes and greater cover plate deformation as projectile fragments hit deeper, thus increasing resistance against penetration. The findings of this research supported previous work demonstrating SiC ceramics’ use for applications that require ballistic resistance.