Structure and tribological properties of plasma-treated carbide derived carbon layer

The effect of hydrogen plasma treatment on the nanocrystal structure and tribological properties of carbide derived carbon (CDC) was investigated. The CDC layer was formed on a SiC substrate using chlorine gas at 1000°C. The plasma treatment was performed on the CDC layer via plasma-enhanced chemical vapor deposition (PECVD) and plasma exposure times of 1, 3, 5, 10 and 15 h were used. Raman spectra and transmission electron microscopy measurements revealed that the carbon layer of the 5 h-treated CDC layer consisted of nanocrystal phases; prior to the treatment, the carbon layer was mainly composed of amorphous carbon structures. Furthermore, the effect of the plasma treatment on the tribological properties of the CDC layer was investigated. The optimum friction coefficient value of 0.09 and a slightly enhanced wear rate were obtained after the 5 h plasma treatment. These results showed that the plasma treatment transformed the carbon structure of the CDC and increased the amount of sp³-bonded nanocrystal structures. As a result, the tribological properties of the CDC layer were optimized by using the plasma treatment.