Formation of surface deposits on steel and titanium aviation fuel tubes under real operating conditions
Formation of surface deposits on steel and titanium aviation fuel tubes under real operating conditions
In this study, stainless steel and titanium (Ti) tubes obtained from a turbofan engine after the end of its lifetime were analyzed in order to compare the amount of pyrolytic coke present and its influence on the parent, base material. Various analytical techniques including microhardness and topographical evaluations, optical emission spectrometry (OES), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) were applied. On steel surfaces, a thick pyrolytic coke deposition layer consisting of carbon and oxygen and also containing elements from the tube material, fuel, and fuel additives was found. The concentration of elements from the pyrolytic coke continuously decreased with distance from the surface of the deposit, while the concentrations of elements from the tube material continuously increased, with the concentrations of elements from the fuel and the fuel additives being relatively constant. With ultrasonic cleaning in distilled water, most of the deposits could be removed. Only carbon-rich patches with a thickness of more than 300 nm remained adhered to the surface and/or had diffused into the original material. On Ti surfaces, the thickness of the C-rich fuel deposit layer was significantly thinner as compared to that on the stainless steel; however, the surface was covered with an -3 μm-thick oxide layer, which consisted of elements from the fuel additives. It is believed that the beneficial properties of Ti covered with a thin layer of TiO2 , such as low adhesion and/or surface energy, have promoted different deposition mechanisms compared to those of stainless steel and thus prevented pyrolytic coke deposition and the related material deterioration observed on stainless steel.
8255-8273
Velkavrh, Igor
50335daa-6319-4430-9bcc-975324b255db
Palamarciuc, Ion
92f12895-86ff-4642-bf52-b000e91bf13b
Galuşcǎ, Dan Gelu
22e5c625-5b94-4488-ab17-f8113d072ab9
Diem, Alexander
6910f0b7-3982-4ceb-a7bc-a3f7e136955c
Brenner, Josef
1999923b-5d12-4528-9a0b-26e9a32acbb0
Gabler, Christoph
f957b0c5-8c12-42c5-9727-11bd0405914a
Mellor, Brian
2b13b80f-880b-49ac-82fe-827a15dde2fe
Ratoi, Monica
cfeffe10-31ca-4630-8399-232c4bc2beff
8 May 2019
Velkavrh, Igor
50335daa-6319-4430-9bcc-975324b255db
Palamarciuc, Ion
92f12895-86ff-4642-bf52-b000e91bf13b
Galuşcǎ, Dan Gelu
22e5c625-5b94-4488-ab17-f8113d072ab9
Diem, Alexander
6910f0b7-3982-4ceb-a7bc-a3f7e136955c
Brenner, Josef
1999923b-5d12-4528-9a0b-26e9a32acbb0
Gabler, Christoph
f957b0c5-8c12-42c5-9727-11bd0405914a
Mellor, Brian
2b13b80f-880b-49ac-82fe-827a15dde2fe
Ratoi, Monica
cfeffe10-31ca-4630-8399-232c4bc2beff
Velkavrh, Igor, Palamarciuc, Ion, Galuşcǎ, Dan Gelu, Diem, Alexander, Brenner, Josef, Gabler, Christoph, Mellor, Brian and Ratoi, Monica
(2019)
Formation of surface deposits on steel and titanium aviation fuel tubes under real operating conditions.
ACS Omega, 4 (5), .
(doi:10.1021/acsomega.8b03576).
Abstract
In this study, stainless steel and titanium (Ti) tubes obtained from a turbofan engine after the end of its lifetime were analyzed in order to compare the amount of pyrolytic coke present and its influence on the parent, base material. Various analytical techniques including microhardness and topographical evaluations, optical emission spectrometry (OES), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) were applied. On steel surfaces, a thick pyrolytic coke deposition layer consisting of carbon and oxygen and also containing elements from the tube material, fuel, and fuel additives was found. The concentration of elements from the pyrolytic coke continuously decreased with distance from the surface of the deposit, while the concentrations of elements from the tube material continuously increased, with the concentrations of elements from the fuel and the fuel additives being relatively constant. With ultrasonic cleaning in distilled water, most of the deposits could be removed. Only carbon-rich patches with a thickness of more than 300 nm remained adhered to the surface and/or had diffused into the original material. On Ti surfaces, the thickness of the C-rich fuel deposit layer was significantly thinner as compared to that on the stainless steel; however, the surface was covered with an -3 μm-thick oxide layer, which consisted of elements from the fuel additives. It is believed that the beneficial properties of Ti covered with a thin layer of TiO2 , such as low adhesion and/or surface energy, have promoted different deposition mechanisms compared to those of stainless steel and thus prevented pyrolytic coke deposition and the related material deterioration observed on stainless steel.
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acsomega.8b03576
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Accepted/In Press date: 28 March 2019
Published date: 8 May 2019
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Local EPrints ID: 431122
URI: http://eprints.soton.ac.uk/id/eprint/431122
ISSN: 2470-1343
PURE UUID: 0ffe0ecf-798e-44d8-b1b4-5edcddfa8d86
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Date deposited: 24 May 2019 16:30
Last modified: 18 Mar 2024 03:14
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Author:
Igor Velkavrh
Author:
Ion Palamarciuc
Author:
Dan Gelu Galuşcǎ
Author:
Alexander Diem
Author:
Josef Brenner
Author:
Christoph Gabler
Author:
Brian Mellor
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