Scratch adhesion testing of nanophase diamond coatings on steel and carbide substrates

Films of nanophase diamond are deposited in vacuum onto almost any substrate by condensing multiply charged carbon ions carrying keV energies. These ions are obtained from the laser ablation of graphite at intensities in excess of 10¹¹ W cm⁻². The high energies of condensation produce interfacial layers between the film and substrate materials, resulting in levels of adhesion that can support the protection of substrates subjected to harsh environmental conditions. In this article, we give details of the scratch adhesion testing performed on steel and carbide substrates coated with nanophase diamond. A commercially available scratch tester was used and a data analysis was presented to quantitatively assess and measure the adhesion of films on these important substrates. The characterization studies in this work demonstrated nanophase diamond as a highly adherent coating suitable for industrial applications.