AVS 46th International Symposium
    Thin Films Division Monday Sessions
       Session TF+VM-MoA

Paper TF+VM-MoA3
Synthesis of Diamondlike Carbon Films with Superlow Friction and Wear Properties

Monday, October 25, 1999, 2:40 pm, Room 620

Session: Advances in Hard and Superhard Coatings II
Presenter: A. Erdemir, Argonne National Laboratory
Authors: A. Erdemir, Argonne National Laboratory
O.L. Eryilmaz, Argonne National Laboratory
G. Fenske, Argonne National Laboratory
Correspondent: Click to Email
In this study, we introduce a new diamond-like carbon (DLC) film providing friction coefficients of 0.001 and wear rates of 10-9 to 10-10 mm3/N.m in inert gas environments (e.g., dry nitrogen and argon). The film was grown on steel and sapphire substrates in a plasma enhanced chemical vapor deposition system using a hydrogen-rich plasma. Employing a combination of transmission electron microscopy, electron diffraction, Raman spectroscopy, and electron energy loss spectroscopy, we explored the structural chemistry of the resultant DLC films and correlated these findings with their friction and wear mechanisms. The results of tribological tests under a 10 N load (creating an initial peak Hertz pressure of 1 GPa on steel test pairs) and at 0.2 to 0.5 m/s sliding velocities indicated that a close correlation exists between the friction and wear coefficients of DLC films and the source gas chemistry. Specifically, films grown in source gases with higher hydrogen-to-carbon ratios had the lowest friction coefficients and the highest wear resistance. The lowest friction coefficient (i.e., 0.001 on a sapphire substrate) was achieved with a film derived from a gas mixture consisting of 25% methane and 75% hydrogen. The wear-debris particles found in and around the wear scars and tracks were analyzed by Raman spectroscopy and FTIR to elucidate the wear mechanism of DLC films. @FootnoteText@ *Work supported by the U.S. Department of Energy under contract W-31-109-Eng-38.