A szilícium-karbid sűrűsége

Silicon carbide (SiC) is one of the lightest, hardest, and strongest advanced ceramic materials with superior resistance to acids, molten salts, low thermal expansion and abrasion. Furthermore, its strength and rigidity enable it to withstand physical wear such as erosion or wear in spray nozzles or other components of an application.

Acheson first pioneered commercial production of SiC in 1891 through reaction bonding or sintering methods.

Sűrűség

Silicon carbide (SiC) is an inorganic chemical compound consisting of silicon and carbon. Found naturally as the rare mineral moissanite, SiC has also been mass-produced as powders or single crystals since 1893 and used as an abrasive. Furthermore, SiC ceramic plates used for bulletproof vests contain this material, as well as being grown as semiconductors to create bright red LED lights whose greenish-blue light makes a good abrasive surface material.

Silicon carbide has an exceptionally dense density of 3.21 g cm-3, making it one of the densest compounds on Earth. Though insoluble in water, it can be dissolvable with alkalis such as NaOH and KOH and even iron molten at temperatures higher than 2700 degC. Furthermore, silicon carbide does not quickly react with air or water but can undergo chemical reactions at higher temperatures which produce amorphous silicon dioxide and methane as by-products.

Silicon carbide makes an excellent material choice for space telescopes due to its superior wear resistance and low thermal expansion and rigidity properties. Its low expansion enables telescope mirrors to be cooled without warping or melting during cooling; Herschel and Gaia telescopes have both used silicon carbide mirrors.

Silicon carbide can also be utilized as a raw material for refractories, due to its durability against extreme temperatures. As such, its use as an insulation lining in furnaces and kilns in various industries makes this material an essential part of these coatings. Furthermore, silicon carbide plays a significant role in producing glass and ceramic materials.

Silicon carbide demand worldwide is expanding quickly, especially in Asia Pacific. This region’s rapid expansion can be attributed to an upsurge in electric vehicle sales and charging infrastructure investments; furthermore, increasing interest in renewable energy sources should drive demand for silicon carbide in this region.

STMicroelectronics N.V. of Switzerland, Infineon Technologies AG of Germany, Semiconductor Components Industries LLC from the US, WOLFSPEED INC of US, ROHM Co Ltd from Japan are among the market players that are actively expanding their presence in global silicon carbide market. To do this, these players have implemented both organic and inorganic growth strategies such as product launches, agreements, partnerships, collaborations contracts acquisitions or expansions to strengthen their positions within this global industry.

Young’s Modulus

Silicon carbide is one of the hardest ceramic materials on Earth, capable of withstanding high temperatures and chemical environments in addition to being highly resistant to corrosion, abrasion and erosion. Due to these characteristics, silicon carbide makes an excellent construction material with excellent fatigue strength and dimensional stability properties.

Young’s modulus is a material property that measures elastic properties of samples, quantifying how much force is necessary to cause deflection under load. A tensile test can be used to calculate Young’s modulus while its slope can provide information on bending stress calculations and can allow engineers to assess whether new materials will meet specific application criteria.

This research explores the stability, mechanical, and thermodynamic properties of b-Si1-xC by performing first principles calculations using density functional theory (DFT),38 as implemented in Cambridge serial total energy package (CASTEP). Interaction between ions and electrons are represented via the plane augmented wave pseudopotential method; exchange and correlation functions among atoms can be described either with local density approximations or generalized gradient approximations; in turn increasing doping increases density, molar volume, and Young’s modulus properties as doping does b-Si1-xC.

In another study, 100-nm and 300-nm thick a-SiC films were grown using PECVD and their characteristics were studied using ellipsometry, AFM, and XRR. Thermal conductivity and Young’s modulus did not show significant scale effects while mass density of these thin films was significantly lower than that of bulk SiC due to reduced bond density within microstructures. Finally, mechanical properties like high Young’s moduli and stability were observed within them.

Porosity of materials can be directly tied to its Young’s modulus via its Poisson ratio, since Poisson ratio decreases as density does; using this relationship, one can calculate dynamic Young’s modulus using its sonic log. Formularyly:

Hővezető képesség

Silicon carbide (SiC) is an attractive semiconductor material with excellent thermal conductivity and low thermal expansion coefficient, making it suitable for many heat generation or transfer applications. SiC can be found in mirrors of astronomical telescopes due to its light weight and rigidity; furthermore, its high temperature resistance and thermal conductivity help mitigate against distortion or degradation during operation.

Thermal conductivity in SiC is determined by its composition and structure, with stoichiometric varieties having higher thermal conductivities than off-stoichiometric varieties due to free electrons having much smaller effects on lattice vibration than phonons, the main source of thermal energy generated from vibrating crystals. Off-stoichiometric varieties may increase in thermal conductivity with the addition of small amounts of Si or C; however, its overall thermal conductivity still trails behind that of pure SiC due to free electrons having much smaller impacts on lattice vibration than phonons which generate thermal energy thermally.

There are two major polymorphs of SiC: alpha silicon carbide (a-SiC), with a Wurtzite crystal structure, and beta silicon carbide (b-SiC), featuring zinc blende crystal structure. A-SiC forms the more prevalent variety with wide commercial applications while the latter have seen less commercial activity to date.

Recent research examined the effect of phase composition and microstructure of b-SiC on its thermal conductivity. The material was manufactured via liquid-phase spark plasma sintering using Y2O3 and Al2O3 as sintering aids; thermal conductivity measurements were then compared with that of its parent material b-SiC and results demonstrated its correlation to phase composition/microstructure of its sintering mixture.

Thermal conductivity for pure bulk aluminum (Al) is 237 W/mK, but often much lower for thin films. A thermal analysis and ultrasonic response measurement technique was utilized to analyze thin films made from a-SiC with similar results – kAl = 210 + 10 W/mK which corresponds with values reported in literature regarding bulk a-SiC.

Korrózióállóság

Silicon carbide’s corrosion resistance in acidic or alkaline environments is extraordinary, making it an ideal material for many harsh applications where other materials like metal would degrade quickly. Silicon carbide also makes an excellent material choice for mechanical seals that must function in hostile chemical environments.

Silicon carbide’s corrosion-resistance is partly attributable to its unique structure. It crystallises in an interlocked, close-packed arrangement composed of covalently bonded atoms that form primary coordination tetrahedra with four carbon and four silicon atoms linked by corners into polytype structures called polytypes; such an arrangement and structure also account for silicon carbide’s high thermal conductivity.

Silicon carbide in its purest form is an electrical insulator; however, with careful addition of impurities – known as dopants – it can become an electrical semiconductor. By doping silicon carbide with aluminum, boron and gallium dopants for P-type semiconductor use; nitrogen and phosphorus dopants produce N-type semiconductor devices for specific purposes.

Silicon carbide is widely utilized for use in abrasive machining processes such as sandblasting, grinding and water-jet cutting due to its hardness and durability. Lapidary work often makes use of silicon carbide due to its long lifespan and wear-resistance properties; additionally it serves as an excellent material choice due to lapidary work’s longevity and dimensional stability. Furthermore, in manufacturing applications it serves as furnace lining material as well as being utilized in various metallurgical or refractory applications due to its extreme wear-reresistant properties.

Corrosion resistance is a key factor that determines how fast materials degrade in environments. Therefore, selecting an inorganic coating material with high melting point, good mechanical properties and an ability to tolerate extreme temperatures is paramount when protecting products against degradation and contamination. Silicon carbide provides these qualities and is therefore an ideal option when selecting coating material.

Today’s processes for producing silicon carbide for use in abrasives, metallurgical, and refractory applications include two methods of production – reaction bonded silicon carbide (RSiC) and sintered silicon carbide (SSiC). Reaction bonded silicon carbide is created by infiltrating mixtures of SiC crystallites with binder under temperature and pressure; Sintered silicon carbide can be produced using pure SiC powder sintered using non-oxide sintering aids – both methods produce products with excellent corrosion resistance as well as extreme hardness/failure resistance resulting in great mechanical properties.