Skip to main content Accessibility help

Measurement of Friction Coefficients Between Diamond-Like Carbon Coated VCR Head Drum And VCR Tapes

  • Kwang-Ryeol Lee (a1) and Kwang Yong Eun (a1)


In order to characterize friction and wear behavior between cylindrical specimens and flexible counterface materials such as magnetic tape, a tribometer is suggested. The tribometer is used to investigate the behavior between video cassette recorder (VCR) head drums and VCR tapes. Friction coefficients of uncoated and diamond-like carbon (DLC) film coated head drums of Al alloy are compared before and after a wear test. Before the wear test, an uncoated head drum shows friction coefficients ranging from 0.22 to 0.3 as the applied tension increases from 200 to 600 gf at the sliding speed of 0.16 m/s. The friction coefficients of DLC coated head drum are 14 to 30 % lower than those of uncoated head drums. At the sliding speed of 4.9 m/s, the friction coefficients of both uncoated and DLC coated drums are reduced to less than 0.1. After the wear test, however, the friction coefficients of uncoated head drums increase to the range from 0.3 and 0.47 depending on the applied tensions. Furthermore, the friction coefficients are not reduced even at the high sliding speed of 4.9 m/s. DLC coated head drums, on the other hand, exhibit similar friction coefficients to those before the wear test. Degradation of frictional property in the uncoated head drum is discussed in terms of the surface damages mainly due to magnetic metal oxide particles transferred from VCR tapes. This result shows that the DLC coating of VCR head drum can improve the friction and wear properties. It is also observed that the DLC coating can reduce the damage of VCR tapes.



Hide All
1. Nikkei Electronics Asia, 9, 41 (1993).
2. Enke, K., Dimingen, H. and Dubsch, H., Appl. Phys. Lett., 36, 291 (1980); F. Jansen and M. A. Machonkin, Thin Solid Films, 140 , 227 (1986); K. Okada and Y. Namda, J. Vac. Sci. Technol., A 7, 132 (1989); K. Oguri and T. Arai, J. Mater. Res., 5, 2567 (1990); A. K. Gangopadhyay, W. C. Vassell, M. A. Tamor and P. A. Willermet, J. Tribology, 116, 454 (1994).
3. Nakaue, H., Mitani, T., Kurokawa, H., Yonezawa, Y. and Yoshio, H., Thin Solid Films, 212, 240 (1992).
4. Meunier, P. L., Le Texier, F., Coutellier, J. M. and Mackowski, J. M., Mat. Res. Soc. Symp. Proc, 140, 509 (1989).
5. Bhushan, B., Wear, 93, 81 (1984).
6. Lee, K.-R. et al, Synthesis and Applications of Diamond-like Carbon Films, Ministry of Science and Technology of Korea (MOST) report, BSU134-4943-1 (1993).
7. Bhushan, B., Tribology and Mechanics of Magnetic Storage Devices, 1st ed. (Springer-Verlag Press, New York, 1990), Chap. 4.


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed