graphitized

Graphitized refers to a material that has been converted into graphite or has undergone graphitization, the process of transforming amorphous or disordered carbon into crystalline graphite. In practice the term is used for carbon-rich solids such as petroleum coke, carbon fibers, coal tar pitch, or natural carbonaceous materials that have been heat-treated to develop graphite-like structure.

The graphitization process typically involves high-temperature annealing at temperatures above 2500–3000 °C in inert or reducing environments to allow reorganized sp2-bonded carbon layers to form an ordered hexagonal lattice. The degree of graphitization correlates with crystallite size and Raman spectral features; higher graphitization yields higher electrical conductivity, thermal conductivity, and chemical inertness.

Applications include graphite electrodes for steelmaking and aluminum production, anodes for lithium- and sodium-ion batteries, and reinforced composites where improved conductivity and thermal stability are required. Graphitized petroleum coke is widely produced for electrode material; graphitized carbon fiber and carbon composites find use in aerospace, electronics, and nuclear industries.

Natural graphitization occurs in geological processes where carbonaceous materials are subjected to heat and pressure, yielding graphitic carbon within metamorphic rocks. The term is also used when describing artificially graphitized materials to distinguish them from non-graphitized carbons or from natural graphite.