Correlation of nanomechanical and nanotribological behavior of thin DLC coatings on different substrates

The use of tribological coatings with film thicknesses in the submicrometer regime is an increasing field of applications. In this work diamond-like c arbon films with a thickness of 250 nm deposited via plasma enhanced chemic al vapor deposition on different substrates are characterized by nanoindent ation and microscratching in combination with scanning probe microscopy. Th is configuration allows the testing of samples with loads between 1 muN and 10 mN and a high local resolution. First the influence of the substrate is analyzed with respect to the mechanical properties of the film/substrate s ystem. Furthermore effects of different substrates with respect to the fric tion and wear behavior for scratch as well as oscillating tests are observe d. These results are correlated to the results of nanoindentation. The subs trates cover the range of very soft (SU8 photoresist) up to very hard (AlTi C ceramic) materials showing a clear influence on the tribological response of the systems even in case of indenter displacements being small compared to film thickness (e.g. in the low-load regime). (C) 2001 Elsevier Science B.V. All rights reserved.