Authors: Patrícia Cristiane Santana da Silva, Gislene Valdete Martins, Lania Auxiliadora Pereira, Evaldo José Corat, Vladimir Jesus Trava-Airoldi
Abstract: Diamond-like carbon (DLC) films are widely known for their attractive properties. High adhesion between coating and substrate is necessary to ensure these properties. The bombardment by energetic species during growth tends to generate high intrinsic compressive stresses levels, which have several consequences in coating performance. However, this problem can be solved with the deposition of a thin interlayer with intermediary properties. In this work, films were grown on M2 steel using a modified plasma enhanced chemical vapor deposition PECVD pulsed-DC discharge. In order to improve the coating adherence on the substrate, a silicon interlayer was deposited varying the growth time, which generated different interlayer thickness. Tribological tests were performed to study adhesion and friction gradient. Raman spectroscopy was used to verify the structural arrangement of carbon atoms. The results showed that thickness variation in silicon interlayer leads to significative changes in adhesion between coating and substrate.
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Authors: Patrícia Cristiane Santana da Silva, Gislene Valdete Martins, Evaldo José Corat, Vladimir Jesus Trava-Airoldi
Abstract: Excellent tribological properties of hard materials surface are desirable in several sectors of industry. Diamond-like carbon (DLC) coatings are well known for their low friction, excellent wear resistance, and high hardness. In this work, DLC films were deposited on AISI M2 steel using a modified PECVD pulsed-DC discharge. Multilayer of carbon and silicon were grown, alternately. Samples were produced with different layer thickness for carbon and silicon, and the same parameters for each material layer, in order to investigate friction coefficient in each layer, evaluate rate deposition variation and the gradient behavior of different layers. Raman spectroscopy was used to verify the structural arrangement of carbon atoms. The films were also characterized by scanning electron microscopy and EDX. Tribological tests were performed to observe adhesion between layers and substrate, friction, and wear. The results showed the variation of friction coefficient and that deposition rate declines when increasing number of layers.
392
Authors: Lânia Auxiliadora Pereira, Marcelo Brison de Mattos, Evaldo José Corat, Vladimir Jesus Trava-Airoldi
Abstract: The martensitic stainless steel X45CrSi93 is widely used in the automotive industry. One way to improve its properties is the deposition of high adhesiveness DLC films, which are well known for their excellent properties such as high hardness, low friction coefficient, chemical inertness, biocompatibility and excellent wear resistance. In this work, the adhesion between substrate and film was studied, by growing silicon interfaces with different deposition parameters. The technique used for growing these films was PECVD pulsed-DC. In order to obtain information of the silicon interface formation, ionic sub-implantation simulations were performed, by the software SRIM/TRIM. Raman spectroscopy was used to verify the atomic structure of the films. Scratch tribological test was performed to study adhesion. It was observed that the mechanical and tribological properties were greatly improved with the deposition of DLC films on the silicon interface. A correlation between the residual stress and adhesion of DLC films was found.
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