Deposition of carbonaceous films in AISI D6 steel using the cathodic cage technique

ABSTRACT In this work, thin films of diamond-like carbon DLC (Diamond-like carbon) were deposited on substrates of AISI D6 tool steel by means of the plasma deposition technique with cathodic cage of graphite, with the objective of evaluating the influence of the treatment parameters, such as the duration of the treatment and the polarization of the samples. The treated samples were evaluated in terms of morphology and structure by X-ray Diffraction (XRD), Raman Spectroscopy and Scanning Electron Microscopy (SEM). The results of the diffractograms indicated the presence of the ferrite, graphite and diamond structures for the samples treated with alumina and the formation of graphite with hexagonal structure for treated samples without alumina. The Raman spectra identified the D and G bands characteristic of graphite materials and the best results were obtained for samples that did not use alumina. Micrographs of the films using alumina indicated structures in the form of tiny particles, with clearer and defined contours. As for the non-alumina samples, the DLC films presented a more uniform appearance and coalescence of the grains. The layers of the alumina treated samples had the highest layer thicknesses, especially for the treated sample for 6 hours. Regarding the treatments without alumina, the samples treated for 5 and 6 hours presented on average the highest layer thickness. Thus, it was possible to affirm that the alumina and, also, the time of treatment influence in a significant way the characteristics of microstructure and final thickness of the film.