Page 127 - 摩擦学学报2025年第10期

1524 摩擦学学报（中英文） 第 45 卷

magnetron sputtering device. The device consists of a argon gas (mass fraction 99.999%) was introduced into
vacuum chamber, a vacuum pump set, and an electric the chamber, and a bias voltage (DC, 450 V) was applied
control system. The sample holder was located at the to the substrate. The samples were sputter-cleaned in the
bottom of the chamber, and a direct current (DC) pulse argon plasma. Then the CrN inter-layer was prepared by
power was applied to the sample holder. The sputtering sputtering Cr target (99.99%) in argon and nitrogen
target was fixed at the top of the vacuum chamber, and mixture gas. FeCrAl coatings were deposited on CrN
the distance between the target and the sample was set to layer by simultaneously sputtering the Fe and CrAl
8 cm. Radio frequency (RF, 13.56 MHz) power was target (Cr:Al=65:35%) at 500 ℃. For comparison, a
used for sputtering the Cr target (99.99%), and DC FeCrAl coating was directly deposited onto Zr. FeCrAl
power was used for sputtering the Fe and CrAl targets. coatings with and without CrN layer were labeled as
Using a vacuum pump set created a high vacuum FeCrAl/CrN and FeCrAl, respectively. Further details
environment inside the chamber at room temperature, regarding the substrate deposition process were outlined
−4
when the background pressure dropped below 5×10 Pa, in Table 1.

Table 1 The main technological parameters of coating preparation
Coatings Target Sputtering power/W Pressure/Pa Gas Bias voltage/V Time/h
CrN Cr 250 0.5 Ar/N 2 10 6.5
FeCrAl Fe, CrAl 300 0.4 Ar 70 3.0
FeCrAl/CrN Cr, Fe, CrAl 250, 300 0.5, 0.4 Ar, Ar/N 2 10, 70 9.5

2.2 Experimental Methods The adhesion performance was judged by observing the
The cross-sectional morphology and thickness of shape, number, and peeling phenomenon of cracks at the
the coatings were examined using a scanning electron edge of the indentation and was divided into six grades
microscope (SEM, ZEISS Gemini SEM 300). The (HF1-HF6). Among them, HF1, HF2, HF3, and HF4
microstructure of the coatings was analyzed using an X- indicate good adhesion, while HF5 and HF6 indicate
ray diffractometer (XRD, TD-3500) with a grazing poor adhesion [21-22] .
incidence angle set at 3°. The hardness and elastic The frictional properties of the FeCrAl coatings in
modulus of the coatings were measured using nano- simulated primary cooling B-Li water and air were
indentation equipment (KLA, G200), a Berkovich evaluated using a tribometer (TRN). The normal load
indenter with a tip diameter of 20 nm was used to was set at 2 N, the friction stroke was 1 mm, the
penetrate the surface of the sample, with a maximum reciprocating frequency was 10 Hz, and the wear cycles
depth of 1.5 µm. The depth exceeds 1/7 of the coating were set to 5 000. A ZrO ball with a diameter of 6 mm
2
thickness, and the measured nano-hardness represented was used as the friction counter. The wear morphology
the combined hardness of the coating-substrate system. of the coatings was analyzed using a three-dimensional
Each sample underwent 9 tests at different locations, and white light interferometer (GT-K), SEM and an optical
the average values of them were used to represent the microscope (ZEISS Axio Imager A1m). In addition, the

hardness and elastic modulus of the coatings and Zr-4. chemical composition of the wear track was analyzed
The coating-substrate adhesion performance of the using an energy-dispersive spectrometer (EDS) and a
coatings and the Zr-4 substrate was evaluated using the Raman spectrometer (Finder Vista).
indentation method (VDI 3198) [21] . Five indentations
were made at different locations on the coating under a 3 Results and analysis
load of 150 kg by using a Rockwell hardness tester, and 3.1 Microstructure and composition of coatings
the morphology of the indentation was observed using Fig. 2 showed the surface morphology of FeCrAl/
an optical microscope at a magnification of 100 times. CrN and FeCrAl coatings, which were dense and free