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Tantalum carbides (TaC) form a family of binary chemical compounds of tantalum and carbon with the empirical formula TaC x, where x usually varies between 0.4 and 1. They are extremely hard , brittle, refractory ceramic materials with metallic electrical conductivity .
Tantalum is a chemical element; it has symbol Ta and atomic number 73. It is named after Tantalus, a figure in Greek mythology. [11] Tantalum is a very hard, ductile, lustrous, blue-gray transition metal that is highly corrosion-resistant.
The beta phase is hard and brittle; its crystal symmetry is tetragonal (space group P42/mnm, a = 1.0194 nm, c = 0.5313 nm), Knoop hardness is 1000–1300 HN and electrical resistivity is relatively high at 170–210 μΩ⋅cm. The beta phase is metastable and converts to the alpha phase upon heating to 750–775 °C.
The phase diagram shows, in pressure–temperature space, the lines of equilibrium or phase boundaries between the three phases of solid, liquid, and gas. The curves on the phase diagram show the points where the free energy (and other derived properties) becomes non-analytic: their derivatives with respect to the coordinates (temperature and ...
118 chemical elements have been identified and named officially by IUPAC.A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z).
English: Theoretical phase diagram of carbon, which shows the state of matter for varying temperatures and pressures. The hatched regions indicate conditions under which one phase is metastable, so that two phases can coexist. The source reference says that the phase diagram is well established only up to around 100 GPa.
In each of the three classes of Laves phase, if the two types of atoms were perfect spheres with a size ratio of /, [2] the structure would be topologically tetrahedrally close-packed. [3] At this size ratio, the structure has an overall packing volume density of 0.710. [ 4 ]
The MAX phases are layered, hexagonal carbides and nitrides which have the general formula: M n+1 AX n, (MAX) where n = 1 to 4, [1] and M is an early transition metal, A is an A-group (mostly IIIA and IVA, or groups 13 and 14) element and X is either carbon and/or nitrogen.