# Friction and Wear Performances of Materials for Wind Turbine Sliding Bearing Bushes
## 5 Conclusions  
In addressing the investigation of fan plain bearing materials operating under low-speed and heavy-load conditions, this study employed laser cladding technology to apply CoCrFeNiMo high-entropy alloy coating on the surface of 9 Cr18 bearing steel and Ni-Cr-Mo-Si alloy coating on the surface of MTCrMoCu30 wear-resistant cast iron. Macroscopic morphology as well as friction and wear properties were meticulously observed and analyzed, yielding the following conclusions:  
1. Optimal laser power settings were determined through numerical simulation and single-pass cladding experiments. For CoCrFeNiMo high-entropy alloy coating on 9 Cr18 bearing steel, the ideal power was determined to be 1300 W. While the coating exhibited strong interlayer bonding, the surface appeared dark yellow and rough. In the case of Ni-Cr-Mo-Si alloy coating on MTCrMoCu30 wear-resistant cast iron, the  
Figure 11: Surface wear and morphology of the two groups of materials: (**a–c**) CoCrFeNiMo high-entropy alloy coating; (**d–f**) Ni-Cr-Mo-Si alloy coating; (**a,d**) 30 N; (**b,c**) 40 N; (**c,f**) 50 N.  
Figure 12: Microstructure of wear marks on the surface of the two groups of materials: (**a–c**) CoCrFeNiMo high-entropy alloy coating; (**d–f**) Ni-Cr-Mo-Si alloy coating: (**a,d**) 30 N; (**b,c**) 40 N; (**c,f**) 50 N.  
optimal power was found to be 1000 W, resulting in a tightly bonded coating with a flat surface.
2. The CoCrFeNiMo high-entropy alloy coating demonstrated a minimum mean friction coefficient of 0.45 at a 50 N load, with a minimum wear mass of 2 mg achieved at a 40 N load. Conversely, the Ni-Cr-Mo-Si alloy coating exhibited a minimum mean friction coefficient of 0.49 at a 30 N load, with a minimum wear mass of 0.7 mg achieved at a 50 N load. With an increase in applied load, the friction coefficient, wear quality, and wear rate of CoCrFeNiMo high-entropy alloy coating initially decreased and then increased. Conversely, the friction coefficient of Ni-Cr-Mo-Si alloy coating increased with the applied load, with wear quality and wear rate initially increasing and then decreasing.
3. The friction curve of CoCrFeNiMo high-entropy alloy coating displayed considerable fluctuation, resulting in relatively large wear volume and wear rate. In contrast, the friction coefficient of Ni-Cr-Mo-Si alloy coating remained relatively stable, with low wear quality and wear rate. Comparatively, the overall priority index of Ni-Cr-Mo-Si alloy coating was higher. Therefore, Ni-Cr-Mo-Si alloy coating, prepared on the surface of MTCrMoCu30 wear-resistant cast iron using laser cladding technology, effectively enhances the friction and wear properties of sliding bearing bush.
4. In the experimental load range, the wear depth of CoCrFeNiMo high-entropy alloy coating initially increased and then decreased with the applied load, while wear scar length and wear surface area initially decreased and then increased. The predominant wear mechanism observed was abrasive wear. Conversely, the wear length of Ni-Cr-Mo-Si alloy coating initially decreased and then increased, with wear depth and wear surface area increasing. The wear mechanism for this coating involved the coexistence of adhesive wear and abrasive wear.  
Methodology, J.M.; Software, J.C.; Validation, J.C.; Investigation, L.L. and X.L.; Resources, J.M.; Data curation, J.C.; Writing--original draft, J.C.; Writing--review & editing, J.M., L.L. and X.L.; Supervision, L.L. and X.L.; Funding acquisition, J.M. All authors have read and agreed to the published version of the manuscript.  
This research is supported by the Key R&D Program of Xinjang Province (Grant No. 2022B01017).  
Not applicable.  
The original contributions presented in the study are included in the article, further inquiries can be directed to the corresponding author.  
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.