Experimental Study of Diamond-like Carbon Film on Aermet100 Steel and First-Principles Calculation of Interfacial Adhesion

Three different types of surface-modified layers of N, C, and N+C are successfully prepared on AerMet100 steel by plasma-assisted thermochemical treatment, and diamond-like carbon (DLC) films are formed on the top surfaces of the latter two. The results show that the DLC films produced by prenitriding and then carburizing (N+C) exhibit a smoother and finer morphology and higher sp3 content than that without prenitriding (C). In addition, the wear resistance of the N+C specimen with a high hardness nitrided layer as the support for the outermost DLC films is superior to that of the C specimen. In view of the catalytic effect of the Fe3C phase on the growth of DLC films, the interfacial properties of Fe3C(001)/diamond(111) are investigated using first-principles calculations. On the basis of the most preferred Fe-terminated HCP site model, the effects of alloyed cementite (Fe2MC) on interfacial adhesion of Fe2MC(001)/diamond(111) are also investigated. Furthermore, the mechanisms of interfacial adhesion for two representative dopings (Zr weakened and V enhanced) are revealed in detail. These results are expected to provide a potential promising means for future experimental works on the preparation of high-performance DLC films on alloy steel surfaces by plasma carburizing.

Automated summary

Different surface-modified layers were successfully prepared on AerMet100 steel by plasma-assisted thermochemical treatment, and diamond-like carbon (DLC) films were formed. DLC films produced by prenitriding and then carburizing exhibited better morphology, quality, and wear resistance. The effects of Fe3C phase and alloyed cementite (Fe2MC) on interface adhesion were investigated using first-principles calculations.