Adhesion strength of DLC films on glass with mixing layer prepared by IBAD

The improvement of the adhesion of diamond-like carbon (DLC) films has been tried by ion beam assisted deposition (IBAD). The adhesion strength must b e quantitatively evaluated and determined in order to confirm the improving effect of the adhesion of DLC films by LEAD. In this study, DLC films were prepared on a grass substrate with a mixing layer prepared by IBAD. For th e samples, the scratch tests were carried out using a scratch tester with a CCD camera and two AE sensors. The detachment process of the DLC film duri ng a scratch test was observed and the detachment area was measured. On the other hand, AE signals were detected corresponding to the detachment of th e DLC film, and the force causing the detachment was determined by analyzin g the signals. The adhesion strength of DLC films was calculated from the d etachment area and the force. From that result, the adhesion strength of DL C films without a mixing layer was 3.2 MPa. When the mixing layer was forme d by IBAD with a condition of Ar-30 kV and 2.1 mu A/cm(2), the adhesion str ength increased to 10.7 MPa. Furthermore, that increased up to 44 MPa in th e case of 21.0 mu A/cm(2). Therefore, it was realized that IBAD improved th e adhesion of DLC films and the effects were made clear quantitatively. (C) 2000 Elsevier Science S.A. All rights reserved.