Picture of a black hole

Strathclyde Open Access research that creates ripples...

The Strathprints institutional repository is a digital archive of University of Strathclyde's Open Access research outputs. Strathprints provides access to thousands of research papers by University of Strathclyde researchers, including by Strathclyde physicists involved in observing gravitational waves and black hole mergers as part of the Laser Interferometer Gravitational-Wave Observatory (LIGO) - but also other internationally significant research from the Department of Physics. Discover why Strathclyde's physics research is making ripples...

Strathprints also exposes world leading research from the Faculties of Science, Engineering, Humanities & Social Sciences, and from the Strathclyde Business School.

Discover more...

The corrosion behaviour of macroparticle defects in arc bond-sputtered CrN/NbN superlattice coatings

Wang, H W and Stack, M M and Lyon, S B and Hovsepian, P. and Munz, W D (2000) The corrosion behaviour of macroparticle defects in arc bond-sputtered CrN/NbN superlattice coatings. Surface and Coatings Technology, 126 (2-3). pp. 279-287. ISSN 0257-8972

Full text not available in this repository. (Request a copy from the Strathclyde author)

Abstract

The investigation concerned the corrosion behaviour of macroparticle and growth defects in PVD CrN/NbN superlattice coatings formed by are bond-sputtering (ABS) process on a mild steel BS6323. The electrochemical behaviour of the coatings was firstly studied by potentiodynamic polarising in de-aerated 0.5 M (Na2CO3-NaHCO3) buffer and 5% NaCl solutions, respectively. The coating and defects were then examined in planar view and cross-section by scanning electron microscopic analyses and the results were compared with those prior to the electrochemical measurement. It is found that the overall coating/substrate corrosion process is closely related to the deleterious effect of the macroparticles and growth defects in the PVD coatings. It is further demonstrated that for through thickness macroparticle inclusions, corrosion initiates by galvanic or crevice corrosion between the defect and the coating matrix, subsequently permitting solution access to those defects with eventual substrate pitting and corrosion at the coating/substrate interface. On the basis of the experimental findings and the macroparticle formation theory, the mechanisms of the growth defect-related coating/substrate corrosion are finally proposed. (C) 2000 Published by Elsevier Science S.A. All rights reserved.