Eur. Phys. J. B 8, 493-496 (1999)
https://doi.org/10.1007/s100510050716

Adhesion and its influence on micro-hardness of DLC and SiC films

¹ 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

Received: 30 June 1998
Published online: 15 April 1999

Abstract

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.