Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Tribological assessment of carbon nanotubes films produced by plasma-enhanced chemical vapour deposition: a comparison between dry and wet conditions
Submission Author:
Tainan Andrioni , SC
Co-Authors:
Tainan Andrioni, Cristiano Binder, Tatiana Bendo, Thiago de Souza Lamim
Presenter: Tainan Andrioni
doi://10.26678/ABCM.COBEM2023.COB2023-0928
Abstract
With the increasing concern about the ecological impact of human behavior, multiple areas are raising attention and focusing on diminishing the impact of human actions on global warming.Recent studies conducted in the field of tribology have shown that lubrication and wear protection of tribological contact can significantly reduce CO2 emissions and increase energy savings. In this aspect, carbon-derived materials have been presented as a high-potential solution to reduce friction and wear, acting as solid lubricants. A series of allotropes of carbon are synthesized and used as lubricants, such as graphite, turbostratic graphite and carbon nanotubes, which have good behavior providing a protective tribolayer that significantly reduces wear and friction. Besides the dry conditions performance, well known in the literature, the behavior of carbon nanotubes film in wet conditions is, yet, little explored. Within this context, the main objective of this study is to explore the potential of carbon nanotubes (CNT) films obtained via plasma-enhanced chemical vapour deposition (PECVD) as lubricant in a wet starvation condition (with 5 μl of oil). Two carbon nanotubes films with different morphological and structural aspects were produced, and evaluated with Raman Spectroscopy, Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Tribological characterisation (scuffing resistance, steady-state friction coefficient, specimen and counter-bodies wear rates) was performed using dry and wet conditions, constant and variable load reciprocating sliding tests. The sample wear marks were analyzed with the aid of profilometry and SEM, while the counterbody wear marks were observed in optical microscopy. The CNTs morphologies showed bamboo-like structures able to reduce the friction coefficient from 0.4 to 0.1 at dry conditions. The cementite layer obtained also has shown a relevant impact on the tribosystem behavior, with different layers thickness obtained for the two morphologies. The friction coefficient showed similar results in wet conditions (5 μl of oil) regardless of the characteristics of the nanotubes. The synergy between CNT film and oil showed better results in terms of wear resistance compared to the non-CNT film in the wet conditions. Overall, the addition of oil decreased the tribological performance of the carbon nanotubes films.
Keywords
nanotubes, Tribology, PECVD, lubrication
