LI Wei,LI De-xiang,LU Zhi-jie,LIU Ye-cheng,LYU Xiao-wen,XU Zhi-biao.Effect of Carbon Content on the Microstructure and Tribological Properties of MoCN Nanocomposite Coating Prepared by Medium Frequency Magnetron Sputtering[J],52(4):184-191
Effect of Carbon Content on the Microstructure and Tribological Properties of MoCN Nanocomposite Coating Prepared by Medium Frequency Magnetron Sputtering
  
View Full Text  View/Add Comment  Download reader
DOI:10.16490/j.cnki.issn.1001-3660.2023.04.015
KeyWord:medium frequency magnetron sputtering  nanocomposite coating  MoCN  microstructure  mechanical property  tribological property
                 
AuthorInstitution
LI Wei School of Mechanical and Electrical Engineering, Lingnan Normal University, Guangdong Zhanjiang , China
LI De-xiang School of Rail Transportation, Wuyi University, Guangdong Jiangmen , China
LU Zhi-jie School of Rail Transportation, Wuyi University, Guangdong Jiangmen , China
LIU Ye-cheng School of Rail Transportation, Wuyi University, Guangdong Jiangmen , China
LYU Xiao-wen School of Rail Transportation, Wuyi University, Guangdong Jiangmen , China
XU Zhi-biao School of Rail Transportation, Wuyi University, Guangdong Jiangmen , China
Hits:
Download times:
Abstract:
      In practical engineering application, in order to reduce the damage of parts in the process of friction and wear, coatings are often deposited on the metal surface to improve the wear resistance of parts. MoN coating is a candidate material for tool coating because of its excellent wear resistance. Moreover, by introducing C atom into MoN coating, C and N combine to form nanocomposite structure, which can effectively improve the hardness and anti-oxidation performance of MoN coating. The work aims to explore and prepare MoCN nanocomposite coating with low friction factor and good wear resistance to greatly improve the hardness and wear resistance of mechanical part surface. In this study, MoCN nanocomposite coatings with different carbon contents were prepared by controlling the amount of C2H2 gas (99.99% purity, 0 mL/min, 3 mL/min, 6 mL/min and 9 mL/min) on stainless steel substrates and silicon wafers with medium frequency magnetron sputtering. The effects of carbon content on the microstructure, mechanical properties and tribological properties of the coatings were investigated. The main phase structure of the coating was analyzed by X-ray diffraction and Raman spectroscopy. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the surface and section morphology of the coating. The nano-hardness and elastic modulus of the coating were measured by continuous stiffness method and Nano-indentation. The adhesion strength between the coating and the substrate was evaluated by automatic scratch tester and optical microscope (OM). Finally, the wear test was carried out by the multifunctional friction and wear tester, the wear morphology of the tested coating was analyzed by SEM, and the tribological properties of the coating were evaluated. According to the characterization results of coating microstructure and mechanical properties, MoCN coating was a polycrystalline structure composed of MoN phase and amorphous carbon phase. With the increase of carbon content, the surface roughness of the coating decreased from 11.60 nm to 6.80 nm, and the coating grains were refined. From the cross-sectional morphology of the coating, it could be observed that the MoN coating grew in an obvious loose columnar shape and there were a large number of microporous defects. With the doping of carbon, the columnar crystal growth mode was gradually refined to form a dense microstructure. In addition, from the mechanical property characterization results, it could be seen that the carbon content of the coating had a significant impact on the mechanical properties of the coating. The main performance was that with the increase of carbon content in the coating, the hardness of the coating increased from 7.36 GPa to 10.23 GPa, showing a gradual increasing trend. At the same time, the ability to resist elastic-plastic deformation was gradually enhanced. However, during the scratch test, the abrupt load of acoustic emission signal decreased from 13.80 N to 6.90 N, indicating that the adhesion strength of the coating decreased gradually due to the increase of residual stress. During the wear test, the amorphous carbon element in the coating had a good lubrication effect after graphitization. Therefore, with the increase of carbon content in the coating, the friction coefficient of the coating decreased from 0.85 to 0.51. The wear resistance of the coating was enhanced. The main wear mechanisms in the wear process were adhesive wear, abrasive wear and spalling. It can be seen that with the increase of carbon content in the coating, the columnar growth mode of the coating is gradually refined to form a dense microstructure, and the mechanical and tribological properties are gradually improved.
Close