Details

Autor(en) / Beteiligte

• Santos, N.M.
• Mariano, S.F.M.
• Ueda, M.

Titel

Carbon films deposition as protective coating of titanium alloy tube using PIII&D system

Ist Teil von

• Surface & coatings technology, 2019-10, Vol.375, p.164-170

Ort / Verlag

Lausanne: Elsevier B.V

Erscheinungsjahr

2019

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The purpose of this work is to deposit carbon films inside titanium alloy tube of small diameter, in order to increase the corrosion resistance of its inner surface. The use of carbon films as protective coating can increase the lifetime of the tubes used in propulsion and thermal control systems of satellites. They can also inhibit the permeation of corrosive species, originated from the fuels and the cooling fluids, between the film-metal interface. Titanium alloy tube with 11 mm diameter and 150 mm length, with one side closed configuration was placed inside a vacuum chamber and pulsed to a high energy voltage. Carbon film deposition was performed by using a Plasma Immersion Ion Implantation and Deposition (PIII&D) system. The hollow cathode discharges (HCD) were produced with pulses of 2 kV, 15 A, 20 μs, and 500 Hz of repetition rate, using a RUP-6 pulser. The maximum temperature measured at the surface of tubes was about 1000 °C. The as-deposited carbon films were analyzed in terms of their microstructure, chemical composition, surface morphology and thickness. The surface characterization of the carbon films were carried out by means of Raman Spectroscopy, Field Emission Gun Scanning Electron Microscopy (FEG-SEM), Atomic Force Microscopy (AFM) and Potenciodynamic Polarization tests. The experimental results show an interesting change on the chemical structure of the as-deposited carbon films, when the deposition time varied from 30 min to 240 min, resulting in thicker and quite adhered films on the inner surface of tubes. In addition, the changes on the microstructure, seen by SEM analysis, as well as the ID/IG variation indicate that nanocrystalline graphite (NC-G) films can be deposited on the inner surface of titanium tubes by using this type of PIII&D system. •Properties of carbon films deposited on the inner surface of titanium tubes•Carbon films as protective coating of the Ti-6Al-4V tubes•Plasma Immersion Ion Implantation and Deposition of the carbon films•Carbon film deposited by 120 min was better for corrosion protection of metal tubes.