Hard carbon films and tetragonal zirconia films have been deposited on polycarbonate (PC) substrates using r.f. magnetron sputtering. The structure of the carbon films were deduced from X-ray excited Auger electron spectra (XAES). For what concerns the zirconia films, the chemical and phase structure were determined by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The residual internal stress and the Young’s modulus were investigated. The adhesion properties and scratch hardness were studied using the scratch test and scanning electron microscopy (SEM), for carbon and zirconia films with a comparable stored elastic strain energy. The adhesion failure mechanism appeared of cohesive nature in carbon/PC systems, while failure in zirconia /PC was due to a high internal stress relief. Both kinds of films are found to harden the PC surface, but the carbon films did it at a more extent. While the same critical load was found for both materials in the single-pass scratch test, a better performance was shown by the zirconia films in multi-passes scratch test. A practical work of adhesion of 0.4 J.m-2, calculated on the basis of the model developped by Bull et al., was found for zirconia/PC, while an extrapolated value of 0.03 J.m-2 was obtained for the carbon/PC
Characterization of Carbon and Zirconia Films Deposited on Polycarbonate for Scratch-Proof Coating Applications
Bensaada Laidani, Nadhira;Speranza, Giorgio;Calliari, Lucia;Anderle, Mariano
1998-01-01
Abstract
Hard carbon films and tetragonal zirconia films have been deposited on polycarbonate (PC) substrates using r.f. magnetron sputtering. The structure of the carbon films were deduced from X-ray excited Auger electron spectra (XAES). For what concerns the zirconia films, the chemical and phase structure were determined by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The residual internal stress and the Young’s modulus were investigated. The adhesion properties and scratch hardness were studied using the scratch test and scanning electron microscopy (SEM), for carbon and zirconia films with a comparable stored elastic strain energy. The adhesion failure mechanism appeared of cohesive nature in carbon/PC systems, while failure in zirconia /PC was due to a high internal stress relief. Both kinds of films are found to harden the PC surface, but the carbon films did it at a more extent. While the same critical load was found for both materials in the single-pass scratch test, a better performance was shown by the zirconia films in multi-passes scratch test. A practical work of adhesion of 0.4 J.m-2, calculated on the basis of the model developped by Bull et al., was found for zirconia/PC, while an extrapolated value of 0.03 J.m-2 was obtained for the carbon/PCI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
