Auger and X-Ray Photoelectron Spectroscopy Study of the Tribocontact
Surface after Laser Modification
A.V. Sidashov
1*
, A.T. Kozakov
2
, S.I. Yaresko
3
1
Rostov State Transport University, Rostov-on-Don, 344038 Russia
2
Research Institute of Physics, Southern Federal University, Rostov-on-Don, 344090 Russia
3
Lebedev of Physics, Samara Branch, Russian Academy of Sciences, Samara, 443011 Russia
sav_teor_meh@rgups.ru
Keywords: Auger electron spectroscopy, X-ray photoelectron spectroscopy, laser treatment, tool
steel, oxide films, tool wear out.
Abstract. The samples of the tool steel P6M5 were modified by means of laser irradiation
(hereinafter - LO). The chemical composition of the sample surface before and after the LO was
studied using the Auger and X-ray photoelectron spectroscopy (hereinafter - AES and XPS
respectively). It was found that while the steel is exposed to LO, the thick oxide layer consisting
mainly of the Fe
2
O
3
oxide is formed. It was established that the modification with LO leads to
increasing of wear resistance and durability of the R6M5 steel because of a double reduction of the
friction coefficient.
Introduction
Modification of the surface using a pulsed LO [1 – 6] allows solving a number of important
problems of modern engineering purposefully, in particular to ensure maximum wear resistance of
metal-working tools at the processing of parts by cutting. The exposure on the surface of
multicomponent steels based on pulsed LO iron under different gaseous mediums leads to a
substantial change in the surface composition and a redistribution of the alloying elements in the
depth. All this affects the number of physical characteristics of the surface, including its frictional
properties.
Test methods and materials
The study of sample surface P6M5 steel after pulsed LO with density of laser energy ε ≈ l.8 –
2.0 J/mm
2
[7] was carried out by X-ray photoelectron spectroscopy surface by surface analysis
system SPECS with monochromatization of X-ray AlKα line with the energy of 1486.6 eV and by
Auger electron spectroscopy using ESO - 3 device. The analyzed in the device sample area after the
X-ray monochromatization is about 10 mm
2
(this is approximately a rectangle with side lengths ~ 1-
10 mm
2
). The scanning step in XPS method by energy was 0.1 eV. The energy resolution for the
chosen mode of operation was evaluated through Ag3d
3/2
line and was 0.45 eV. Depth profiling by
AES and XPS combined with ion sputtering was used for the analysis of the modified layers. The
accelerating voltage in the ion gun was 3 kV at current of 3 uA. The rate of removal of steel surface
layers by an ion beam was ~ 3 Å/min. The pressure in the spectrometer preparation chamber of the
sample during ion etching was 5∙10
-3
Pa. Vacuum at survey by XPS method was no worse than
8∙10
-8
Pa. The loading of the sample was evaluated by spectra of C 1s carbon from natural
hydrocarbon contaminants on the surface.
While receiving of Auger spectra the accelerating voltage of the electron gun was 3 kV, the
beam current - 40 uA, the diameter of the electron probe - ~ 3 microns. The pressure in the Auger
spectrometer chamber was no worse than 10
-7
Pa, while during the ion etching the pressure rose to
10
-3
Pa.
Fig. 1 and Fig. 2 shows the X-ray spectra of the steel surface before and after 10 minute pre-etching
[8 – 12]. Ion etching, which removes surface hydrocarbon contamination, the hydroxyl oxygen groups
Materials Science Forum Submitted: 2016-06-12
ISSN: 1662-9752, Vol. 870, pp 298-302 Accepted: 2016-06-14
doi:10.4028/www.scientific.net/MSF.870.298 Online: 2016-09-05
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