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Ultra-high-temperature ceramics (UHTCs) are a type of refractory ceramics that can withstand extremely high temperatures without degrading, often above 2,000 °C. [1] They also often have high thermal conductivities and are highly resistant to thermal shock, meaning they can withstand sudden and extreme changes in temperature without cracking or breaking.
Tantalum carbide is widely used as sintering additive in ultra-high temperature ceramics (UHTCs) or as a ceramic reinforcement in high-entropy alloys (HEAs) due to its excellent physical properties in melting point, hardness, elastic modulus, thermal conductivity, thermal shock resistance, and chemical stability, which makes it a desirable ...
A subset of ultra-high temperature ceramics (UHTC) includes high-entropy ultra-high temperature ceramics, also referred to as compositionally complex ceramics (CCC). This class of materials is a leading choice for applications that experience extreme conditions, such as hypersonic applications which endure very high temperature, corrosion, and ...
This Group IV interstitial transition-metal carbide is also a member of ultra high temperature ceramics or (UHTC). Due to the presence of metallic bonding, ZrC has a thermal conductivity of 20.5 W/m·K and an electrical conductivity (resistivity ~43 μΩ·cm), both of which are similar to that for zirconium metal.
Scalability of the process is therefore limited by the ability of these special furnaces with mechanical pressing to exert and control high forces over large areas uniformly at very high temperature (usually graphite pistons and molds). The choice of process depends on the desired material properties, cost constraints, and production scale.
For some metals, carbothermic reactions do not afford the metal, but instead give the metal carbide. This behavior is observed for titanium, hence the use of the chloride process. Carbides also form upon high temperature treatment of Cr 2 O 3 with carbon. For this reason, aluminium is employed as the reducing agent.
In the realm of high-entropy materials, HEOs are preceded by high-entropy alloys (HEAs), which were first reported by Yeh et al. in 2004. [6] HEAs are alloys of five or more principal metallic elements. Some HEAs have been shown to possess desirable mechanical properties, such as retaining strength/hardness at high temperatures. [7]
Aluminium carbide is a chemical compound with the chemical formula Al 4 C 3. It is a carbide of aluminium . It has the appearance of pale yellow to brown crystals.