Synthesis Of Carbon Nitride Compound And Preparation Of Carbon Nitride Coating

In this paper, we sum up the development in theoretical prediction and experimental synthesis of carbon nitride (CN) compounds. A kind of CN precursor with turbostratic structure has been prepared by pyrolyzing melamine (C₃H₆N₆), then the CN precursor is used as raw material to synthesize CN compound under high temperature and pressure and CN_X films. The compositions, structures, bonding properties of the precursor, the HT-HP products and CN coating have been characterized by EDX, XRD, SEM and FTIR. The morphology, nanohardness and mechanical properties have been studied by means of Atomic force microscopy (AFM).The experimental results suggest that the initial carbonizing temperature of CN precursor increases with the pressure increasing under a definite temperature. A kind of the CN product with the N/C atomic ratio of 1.553 and more orderly structure was obtained by treating the CN precursor under the condition of the pressure of 5.5 GPa and temperature of 700 ℃. The content of H element in the product is obviously less than that of CN precursor.Amorphous CN_X films are deposited on SiO₂ substrates. The CN_X film obtained at the deposit temperature of 660 ℃ has nano-hardess of 1.25 GPa and shows high elastic recovery of 80⁸5 % after indentation. The friction coefficient of the CN_X film is a constant value of 0.15 under the applied load of nano-indentation ranging from 50 μN to 100 μN.