Micro-Hardness and Adhesion of Diamond-Like Carbon Films

Abstract

Diamond-like carbon films have been synthesized by the pulsed laser deposition under a magnetic field. The hardness of the films was increased considerably. However, due to the large compressive stress in the films, adhesion of the films became a serious problem. Two methods, i.e. laser irradiation of the silicon substrate surface and growing a composition-graded intermediate layer, were used to increase the adhesion. With the variations of the interface conditions, the change of the stress type from compressive stress to tensile stress was observed. By careful choosing the composition change of the intermediate layer, adherent diamond-like carbon films with a thickness of 1145 nm were successfully grown on silicon substrates at 80°C.

Mechanical characterization of copper coatings electrodeposited onto different substrates with and without ultrasound assistance

“…For the evaluation the adhesion properties of thin coatings, Chen-Gao (C-G) method was chosen. [12][13][14][15] This method introduces the composite hardness as a function of the critical reduced depth, b, beyond which the material will have no effect on the measured hardness. The critical reduced depth b represents the ratio between the radius of the plastic zone beneath the indentation and the indentation depth.…”

“…It has been shown that the micro-MECHANICAL CHARACTERIZATION OF ELECTRODEPOSITED COPPER COATINGS 731 hardness testing can be a useful technique in assessing the adhesion of thin films to the substrate. [11][12][13][14][15] The aim of the study was to analyze the hardness response of the selected composite systems and analyze the results of the quantitative assessment of coating adhesion based on the measured composite hardness.…”