Long-Duration Frictional and Wear Performance of the Diamond/DLC Bilayered Film under Water-Lubricating Condition

Abstract:

In the present study, the long-duration frictional and wear performance of the MCD/DLC (Micro-crystalline Diamond / Diamond-like Carbon) bilayered film are investigated under water-lubricating conditions. All friction tests are carried out on a rotation “ball-on-plate” tribotester where the MCD/DLC is slid against with a Φ 6.0 mm Si₃N₄ ball and the whole sliding contact is immersed in deionized water during the sliding process. A full factorial experimental plan is conducted with four sliding velocities ranging from 0.126 to 0.503 m/s and four normal loads from 2 to 8 N. The duration of each sliding process is 24 h. For the sake of comparability, conventional MCD and NCD (nanocrystalline Diamond) films are also adopted under each sliding condition. The results show that the stable coefficient of friction (COF) of MCD/DLC film is ranging from 0.025 to 0.12 under the water-lubricating condition, comparable with the NCD film but much lower than that of single-layered MCD film; in contrast, the top-layered DLC film does not show beneficial effect on enhancing the sliding stability of single-layered diamond films. Moreover, its specific wear rate is estimated at the level of 10^-8 mm³N^-1m^-1, higher than that of MCD or NCD films. The sliding interface is under boundary lubrication condition, high normal load causes more prominent mechanical interactions between two contacted surfaces and thus produces a smoother and cleaner equilibrium sliding interface, which finally results in the decreasing tendency of stable COF as the load rises. Comparatively, the sliding velocity does not exhibit evident influence on the stable COF of the MCD/DLC film.

• Periodical: Advanced Materials Research (Volume 1017)
• Pages: 429-434
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.1017.429
• Online since: September 2014
• Authors: Su Lin Chen, Bin Shen*, Fang Hong Sun
• Keywords: Diamond/DLC Bilayered Film, Hot Filament Chemical Vapor Deposition, Long-Duration Sliding, Tribo-Chemical Reaction, Water Lubricating

References

[1] X. C. Chen, Z. J. Peng, X. A. Yu, Z. Q. Fu, W. Yue and C. B. Wang, Microstructure and tribological performance of self-lubricating diamond/tetrahedral amorphous carbon composite film, Appl. Surf. Sci. 257 (2011) 3180.

DOI: 10.1016/j.apsusc.2010.10.136

[2] M. Amaral, D. J. Carreira, A. J. S. Fernandes, C. S. Abreu, F. J. Oliveira, J. R. Gomes and R. F. Silva, A DLC/diamond bilayer approach for reducing the initial friction towards a high bearing capacity, Wear. 290 (2012) 18.

DOI: 10.1016/j.wear.2012.05.026

[3] H. Hanyu, S. Kamiya, Y. Murakami and Y. Kondoh, The improvement of cutting performance in semi-dry condition by the combination of DLC coating and CVD smooth surface diamond coating, Surf. Coat. Tech. 200 (2005) 1137.

DOI: 10.1016/j.surfcoat.2005.02.022

[4] H. K. Csorbai, G. Kovach, G. Peto, P. Csikvari, A. Karacs, A. Solyom, G. Hars and E. Kalman, Diamond-DLC double layer used in corrosive protective coating, Appl. Surf. Sci. 253 (2007) 5070.

DOI: 10.1016/j.apsusc.2006.11.030

[5] B. Shen, S. Chen and F. Sun, Investigation on the long-duration tribological performance of bilayered diamond/diamond-like carbon films, P I MECH ENG L-J MAT. In Press. (2014).

[6] F. Zhou, K. Adachi and K. Kato, Wear-mechanism map of amorphous carbon nitride coatings sliding against silicon carbide balls in water, 200 (2006) 4909.

DOI: 10.1016/j.surfcoat.2005.04.041