Study on the Mechanic Properties of DLC Films on Different Metal Substrates
To overcome the low adhesion of hydrogen-free DLC films on metal substrates, in this studying, DLC films (0.9μm) were prepared with 3 types of interlayer (2 types of Ti/TiCx/DLC interlayer and 1 type of Ti/TiNx/TiNxCy/DLC interlayer) on different substrates (W18Cr4V, Cr12, GCr15, TC4, 40Cr, 9Cr18 and Cr18Ni9Ti). The internal stress of the films was calculated by the bending of substrate (Si(100)). It was found that it is as high as 3.9GPa, and part of the high residual stress of the DLC films was dissipated through a compound interlayers, and the thick films achieved, and the pull tests found that the adhesion has been highly strengthened with a proper interlayer. The films structure qualities were investigated by Raman spectroscopy and the results indicate that the films have the same structure properties which suggests that the properties of the DLC films can not been affected by substrates. The hardness is about 5000HV, defined by nanoindentation techniques. The frictional properties were investigated by reciprocal sliding tests and the friction coefficient was about 0.1, independent of their substrates. Thus our DLC films may have great potential applications in precision parts tribological application.
M.K. Lei, X.P. Zhu, K.W. Xu and B.S. Xu
D. C. Zhao, N. Ren, Z. J. Ma, G. J. Xiao, S. H. Wu, "Study on the Mechanic Properties of DLC Films on Different Metal Substrates", Key Engineering Materials, Vols. 373-374, pp. 117-121, 2008