Adhesion and its influence on micro-hardness of DLC and SiC films
Department of Physics, The University of Hong Kong, Pokfulam Road, Hong Kong
2 Department of Materials Science and Engineering, Beijing University of Aeronautics and Astronautics, Beijing, P.R. China
Published online: 15 April 1999
Micro-hardness and scratch adhesion testing are the most commonly used techniques for assessing the mechanical properties of thin films. Both of these testing methods utilize single-point contact and induce plastic deformation in the substrate and film. However, the influence of adhesion on the measured hardness has been seldom reported so far. In our experiments, diamond-like carbon (DLC) and silicon carbide (SiC) films deposited on silicon and nickel-based alloy substrates by pulsed laser ablation were indented and scratched by a Vickers micro-hardness tester and a diamond-cutter, respectively. It was found that the composite hardness decreased more rapidly for poor adhesion when increasing the indentation load. The result was explained by the elastic-plastic deformation mode of indentation and helped us to understand the physical meaning of one parameter commonly introduced in the models used to separate film hardness from the composite hardness.
PACS: 62.20.Qp – Tribology and hardness / 68.35.Gy – Mechanical and acoustical properties; adhesion / 81.15.Fg – Laser deposition
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 1999