The Thermal Conductivity and Strength of Silicon Carbide

Silicon Carbide (SiC) is a durable non-oxide ceramic known for its strength and heat resistance. It can be found in applications that demand high thermal endurance with minimal expansion.

SiC’s thermal conductivity rises with temperature up to a certain point; however, due to impurities or structural defects it gradually decreases over time – this phenomenon applies to many materials.


Silver is one of the most ubiquitous metals on earth and boasts high thermal conductivity, making it widely used across industries including solder paste and capacitor production. Silver’s low coefficient of thermal expansion and malleability also makes it suitable for applications that require high thermal flows from substrate to chip such as power electronics solder paste applications.

Silicon carbide is a high-temperature refractory ceramic material with very low electrical resistance (1 ohm cm). Additionally, its thermal conductivity ranges between 120-270 W/mK. Furthermore, this strong material resists oxidation and corrosion as well as being extremely hard. Due to these qualities, silicon carbide makes an ideal material choice for use in applications requiring both wear resistance and high temperatures.

Thermal conductivity of SiC is closely tied to its lattice temperature, which in turn is controlled by electron concentration within its crystal structure. As electron concentration increases, lattice temperature decreases and thermal conductivity increases proportionally. Researchers measured thermal conductivity in face centered cubic polycrystalline SiC produced via chemical vapor deposition (CVD). They discovered that their highest purity sample (3C-SiC) exhibited thermal conductivity that is equivalent to both diamond and copper and 50% higher than commercially available 6H-SiC materials available commercially available 6H-SiC materials available commercially available 6H-SiC materials available commercially available 6H-SiC materials.

Researchers also explored the effects of impurities on CVD SiC thermal conductivity by deliberately doping it with boron and nitrogen dopants, finding that adding boron significantly decreased thermal conductivity – consistent with theoretical predictions made earlier work – while nitrogen doping had no discernible impact on electron concentration in its crystal structure, as evidenced by no decrease in thermal conductivity from doping it with this element.

The authors published their research results in “Applied Physica A,” and disclosed no conflicts of interest that might influence their research reported. Their manuscript was reviewed by at least two independent experts before acceptance; Dr. Michael R. Schreck, Director of the NIST Center for Nanoscale Science and Engineering and Dr. Stephen L. Kost, Professor of Physics from University of Maryland College Park were especially helpful with reviewing and providing suggestions.


Silicon Carbide (SiC) is an inorganic semiconductor material consisting of silicon and carbon. SiC has excellent thermal shock resistance properties that make it suitable for applications requiring low expansion, high heat resistance and rapid temperature changes – ideal for high heat resistance without excessive expansion. Furthermore, SiC also features excellent chemical stability as well as very high thermal conductivity properties.

Thermal conductivity of materials depends upon their composition and the nature of their interfaces between phases, so when used as multi-phase composites such as Al-SiC or Cu-SiC the thermal conductivity depends on both copper and SiC phases interacting, which must be fully investigated to obtain accurate thermal conductivity data for these materials.

Researching the interfaces between copper and SiC has yielded some intriguing findings. One such discovery was that coating SiC with spherical copper particles significantly improves compressibility of MMCs due to their reduced contact area between adjacent particles resulting in less frictional frictional resistance.

Copper’s presence not only increases compressibility of SiC/Cu MMCs but also dramatically enhances their thermal conductivity. This is because SiC and copper have similar crystal structures with significant overlap in lattice parameters allowing energy transfer across their interfaces.

Consideration must be given when using these materials for thermal management applications where thermal conductivity of interface is key. SiC/Cu MMCs in particular can be particularly advantageous in situations in which thermal conductivity of interface must exceed that of bulk material.

One factor contributing to the higher thermal conductivity of SiC/Cu MMCs than pure SiC is the presence of multiple phonon scattering events at their interface, which dramatically increase thermal conductivity by several orders of magnitude.


Silicon carbide is a hard, brittle semiconductor with excellent thermal conductivity that can be transformed into metal by doping it with nitrogen, phosphorus or aluminium atoms. Silicon carbide was one of the first commercially important semiconductor materials; used to construct the “carborundum”, an early crystal radio transmitter patented in 1906. Although pure silicon carbide is colorless due to iron impurities present, industrial products typically display brown to black hues due to impurities present.

Silicon carbide thermal conductivity depends on both its morphology and composition of alloying elements, as well as how much is present in solid solution. Alloying elements add lattice distortion as well as creating new interfaces which scatter electrons differently than existing interfaces, decreasing thermal conductivity by weakening it further.

Cu in an aluminium-silicon carbide alloy has lower thermal conductivity than Al2Cu due to having different crystal structures; this plays an integral role in its mechanical properties and should be taken into consideration during design.

This userobject provides thermal properties of monolithic silicon carbide, including its thermal conductivity and isobaric specific heat capacity as a function of temperature. Furthermore, this userobject provides information regarding its thermal expansion coefficient as a function of both temperature and pressure.

Aluminum bonded silicon carbide (ALTRON) is an engineered product that offers exceptional wear and corrosion resistance at an attractive price point. Moldable into various complex shapes without incurring expensive tooling setup charges, ALTON can also be welded or brazed together with other alloys to complete components more quickly than competing materials.

The ALTRON process employs an innovative proprietary technique to seamlessly fuse alumina and silicon carbide together into an enhanced composite. This product combines their superior physical properties while cutting costs by forgoing traditional hard tooling processes. As a result, large areas of open grain allow for increased machining performance as well as increased tensile strength resulting in dense parts with superior wear resistance, chemical stability, chemical durability, making them suitable for demanding applications.

Other Metals

Silicon carbide is an incredible thermal conductive material with incredible strength and durability, unaffected by acids, alkalis or molten salts; and can withstand temperatures of 1600degC without melting. Thanks to this impressive combination of properties it’s becoming an increasingly popular choice for precision machined parts as well as non-reactive corrosion protection against multiple materials – perfect for harsh environments!

Silicon Carbide stands out for its superior thermal conductivity and low coefficient of thermal expansion, making it an excellent material choice for components that must operate across a range of temperatures. Furthermore, its exceptional strength and chemical resistance help safeguard against damage caused by abrasion, impact vibration and thermal shock exposure; furthermore it boasts great thermal shock resistance allowing repeated exposures without suffering damage to its components.

SiC material’s thermal conductivity increases with temperature as its heat transfer mechanisms become more entropic at higher temperatures, increasing specific heat – the measure of how much energy is necessary to raise its temperature by one Kelvin degree. This results in an increase of its specific heat.

silicon carbide’s low specific heat makes it an excellent material choice for mirrors in astronomical telescopes, with polycrystalline forms being grown through chemical vapor deposition to form hard, strong disks of polycrystalline silicon that are thermally conductive.

Doping polycrystalline silicon with rare earth metals is another way of increasing its thermal conductivity and helping it perform in various applications more effectively. Such dopants can increase thermal conductivity by as much as 30 %, helping improve performance significantly across a wider variety of products.

However, it should be kept in mind that phonon mean free path measurements can be affected by crystal structure and matrix properties; thus limiting their usefulness as accurate measures of thermal conductivity in solids. Therefore, other physical properties of the sample should often be used to obtain reliable thermal conductivity values when comparing experimental or theoretical data sets.

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