【Abstract】Super-hard tungsten carbide coating usually refers to covalent bond compounds (carbides, nitrides) composed of elements of main groups III, IV and V, and elemental substances (diamonds), with single crystals
Species, such as diamond, cubic boron nitride (C-BN>, carbon nitride (C3N4 and CNX), boron nitrogen carbon (BCN) and diamond-like carbon (DLC), etc.. Its hardness is very high, close to normal, super hard coating The hardness of the diamond-like coating is above 800GPA; but some scholars regard the covalent bond compound coating above 400GPA as a super hard coating. The hardness of the diamond-like coating is related to the SP3 bond content.
Generally, the hydrogen-free tetragonal amorphous carbon TA-C is also called amorphous diamond coating, which is regarded as super hard coating, while other diamond-like carbon coatings are regarded as general hard coatings. Except that King Kong is artificially synthesized, there is no natural counterpart. In addition, the hardness of nano-multilayer structure coatings and nano-crystalline composite coatings that have been extensively studied in recent years are also excellent in the hardness range of super-hard coatings, so they are favored by people. Super-hard tungsten carbide coating materials can be divided into one-component (elemental) compounds, binary compounds, ternary compounds, and possibly more super-hard coating materials. The main features are: ①The main characteristics of chemical bonds are covalent bonds, ionic bonds The composition is small; ②The atom radius of the nitroxide carbide elements of the third and third periods in the periodic table is very small.
