Technical ceramics play an essential part in many industrial applications, so engineers and manufacturers must select the appropriate material.
Silicon carbide refractories are resilient materials designed to withstand extreme temperatures, chemical corrosion and other challenging environments. Silicon carbide’s hard surface resists wear well over time.
Excellent heat resistance and low thermal expansion coefficient make this material perfect for applications in metallurgy, automobiles, machinery, aerospace, energy production and national defense as well as many other fields.
Hardness
Silicon carbide is one of the hardest materials on Earth, scoring between 9 to 9.5 on Mohs scale. With a crystal structure similar to diamond and the ability to be produced both cubically and hexagonally forms, silicon carbide stands up well against steel and boron nitride as it offers superior wear resistance but may be damaged easily during mishandling or incorrect machining conditions. Ceramics may offer superior wear resistance but lack this brittle quality which could compromise its integrity over time.
Thermal shock resistance and high-temperature resistance combined with mechanical strength make this material suitable for gas sealing rings and mechanical seal parts used in chemical and high-temperature environments. Zero porosity and low pore density further strengthen its corrosion resistance properties.
Silicon carbide not only offers impressive mechanical properties, but it is also known for its exceptional antioxidant performance. It can withstand temperatures up to 1600 degrees Celsius without experiencing degradation; however, at lower temperatures it oxidizes rapidly.
Additionally, it is extremely straightforward to machine using abrasive grinding tools; comparable in ease to that of aluminum oxide and with higher cutting speeds than its aluminum oxide counterpart. Furthermore, its superior hardness allows for faster cutting speeds, further lowering production costs. Furthermore, its excellent tensile and compressive strengths make it suitable for structural applications like automotive components, as well as its good chemical inertness against acids that may come into contact with it.
Thermal Conductivity
Silicon carbide stands out as one of the hardest materials, scoring 9.5 on Mohs scale. It can be formed into virtually any shape by pressing, injection moulding and extrusion; making it an invaluable industrial material. Furthermore, silicon carbide boasts excellent wear resistance properties as well as good fatigue resistance despite being lightweight ceramic material.
Thermal shock and corrosion resistance is another hallmark of its durability, as is maintaining its high strength up to 1400 degrees Celsius – two properties which make it an ideal structural ceramic material, used across numerous industries. Refractories employ it extensively; for example burner nozzles and jet flame tubes in highly corrosive environments where temperatures may reach extreme levels are some applications where this material has proven its worth; chemical process engineering uses it extensively too for condensing vapours that would otherwise damage metal components into corrosion-proof tubes that prevent corrosion damage to metal components in chemical process engineering processes.
Black silicon carbide, for instance, is an outstanding refractory ceramic for use in lining hearth plates, recuperator tubes, pusher slabs and lightweight kiln furniture such as firing rings, girders and stringers. Other applications of black silicon carbide include using it as an abrasive sintering ceramic to grind steel mill scale and mild steel castings while simultaneously using it sanding cast iron and non-ferrous metal surfaces with reduced surface areas.
Sintered silicon carbide, commonly referred to as either sintered silicon carbide (SSiC) or reaction bonded silicon carbide (RBSiC), comes in both porous and fully dense forms. Saint-Gobain Hexoloy ceramics offer RBSiC with open pores while maintaining high densities – two qualities ideal for creating Saint-Gobain Hexoloy ceramics.
Electrical Conductivity
Silicon carbide possesses outstanding mechanical properties at room temperature, as well as impressive resistance against chemical corrosion, high oxidation resistance, and abrasion. Due to these properties, silicon carbide is widely sought-after material across numerous industrial sectors – automotive, mechanical and chemical among others.
Silicon carbide stands out among other ceramic materials, like alumina and titania, in that its strength remains constant even at high temperatures without weakening. This characteristic makes it perfect for use in high-temperature environments like gas seal rings and mechanical seal parts in gas turbines. Furthermore, silicon carbide has excellent corrosion resistance to various chemicals while withstanding thermal shock shockwaves.
Electrical conductivity of this material is impressive, providing for effective heat transfer. Furthermore, its low coefficient of thermal expansion and very high modulus of elasticity contribute to efficient heat transfer while its hardness and abrasion resistance make for efficient use in everyday applications.
Properties of porous silicon carbide depend on its sintering atmosphere, particle size distribution and second-phase content; for instance, its electrical resistivities vary dramatically with regard to nitrogen-sintered samples; they exhibit two orders of magnitude lower electrical resistivities than their argon-sintered counterparts. Impurity concentration and carrier concentration also play a part, with C-added porous SiC showing increasing conductivity as more additive is added while off-stoichiometric structures featuring constant conductivity regardless of carbon addition. A detailed investigation into these effects was performed using electron probe microanalysis (EPMA).
Corrosion Resistance
silicon carbide’s chemical stability and resistance to corrosive agents is one of the key determinants in its suitability for various applications, while tungsten carbide stands out with exceptional hardness and wear resistance but may succumb to certain environments due to corrosion. Meanwhile, advanced ceramics offer greater chemical and abrasion resistance than their tungsten carbide counterpart.
Ceramic materials offer superior thermal conductivity and thermal expansion coefficient, making them suitable for environments involving rapid temperature shifts. Furthermore, their low density makes these versatile materials suitable for industrial or commercial applications.
Silicon carbide stands out among refractory ceramic options due to its excellent abrasion and corrosion resistance, making it perfect for heavy slurry applications and extreme pumping conditions. Furthermore, silicon carbide has resistance against acids, corrosive chemicals, high temperatures and other environmental threats.
SiC is also capable of withstanding prolonged exposure to oxidizing media, where passive oxidation may heal surface flaws and improve average flexural strength, while active oxidation may decrease it, creating new surface flaws as it occurs. Therefore, monitoring its condition is key – while to increase WC alloy’s corrosion and abrasion resistance additional chromium or molybdenum additives (not used with SiC) could improve these characteristics further.