Page 130 - 摩擦学学报2025年第10期

第 10 期 SU Yongyao, et al.: Exploring the Impact and Mechanism of CrN Interlayer on the Tribological ··· 1527

higher hardness of 10.9±0.5 GPa, enhanced the of FeCrAl，FeCrAl/CrN were higher than Zr-4 substrate,
composite hardness of the FeCrAl/CrN. with the FeCrAl coating exhibiting the highest value of

Good coating-substrate adhesion was a prerequisite 0.7. However, the FeCrAl/CrN coating showed a
for the safe service of the coating. In this study, the reduced friction coefficient of 0.56, as shown in
coating-substrate adhesion performance was evaluated Fig. 7(a). Fig. 7(b) presented the wear rate of the three
using the indentation method (VDI 3198). The surface samples, FeCrAl and FeCrAl/CrN demonstrating a lower
morphology of the indentation was shown in Fig. 6, the wear rate compared to Zr-4 substrate. The FeCrAl/CrN
edge of the indentation in both coatings remains intact exhibited the lowest wear rate of approximately 3.2×
3
−6
without peeling, indicating good coating-substrate 10 mm /(N·m), which was only one-third of the
adhesion. The FeCrAl coating only had sparse and short FeCrAl coating’s wear rate. Thus, the application of
radial cracks at the edge of the indentation, which were FeCrAl coating on the surface of Zr-4 effectively
evaluated as HF1. However, the FeCrAl/CrN coating reduces wear loss, and the addition of the CrN interlayer
had longer radial cracks at the edge of the indentation further enhances the wear resistance of the FeCrAl
and was evaluated as HF3, indicating a slight decreased coating. This could be attributed to the high surface
in coating-substrate adhesion. This may be due to the hardness and excellent load-bearing capacity of the
introduction of the CrN intermediate layer, which makes FeCrAl/CrN coating， which suppressed the plastic
[22] [29-30]
the coating system more brittle . deformation of the coating-substrate system .
3.3 Friction and wear performance Fig. 8 presented the 3D topography, optical
The friction and wear performance of the FeCrAl, microscopy morphology, and cross-sectional profile of
FeCrAl/CrN, and Zr-4 substrate were evaluated in air the wear scars for FeCrAl, FeCrAl/CrN and Zr-4
and B-Ii water. Fig. 7 illustrated the friction coefficient substrate. As shown in Fig. 8(a) and (a1), abundant black
and wear rate of samples in air. The friction coefficient debris accumulated inside the wear track of Zr-4,

(a) (b)

200 μm 200 μm

Fig. 6 Morphology micrographs of indentation optical microscope: (a) FeCrAl; (b) FeCrAl/CrN

1.0 150

(a) (b)
0.8 140
130
Friction coeffiicient 0.6 Wear rate/[10 −6 mm 3 /(N·m)] 120

110
0.4
0.2

0.0 10 0
Zr-4 FeCrAl FeCrAl/CrN Zr-4 FeCrAl FeCrAl/CrN
Fig. 7 Friction coefficient and wear rate of FeCrAl, FeCrAl/CrN coating, and Zr-4 in air: (a) friction coefficient; (b) wear rate