Effects of cathode grain size and substrate fixturing on the microstructure evolution of arc evaporated Cr-cathodes and Cr-N coating synthesis
2014 (English)In: Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films, ISSN 0734-2101, E-ISSN 1520-8559, Vol. 32, no 2, 021515- p.Article in journal (Refereed) Published
The influence of the cathode grain size and the substrate fixturing on the microstructure evolution of the Cr cathodes and the resulting Cr-N coating synthesis is studied. Hot isostatic pressed Cr cathodes with three different grain sizes were arc evaporated in a nitrogen atmosphere and Cr-N coatings were deposited on cemented carbide substrate at 2 and 4 Pa nitrogen pressure, respectively. The Cr cathodes before and after arc discharging are composed of polycrystalline α-Cr regardless of the grain size. A converted layer forms on the Cr cathode surface and its microstructure differs with the cathode grain size. A stationary substrate fixturing results in ditches covering the cathode surface while a single rotating fixturing does not. The increased grain size of the virgin Cr cathodes enhances the quantities of the ditches. The possible causes are addressed. At 2 Pa nitrogen pressure, the Cr-N coatings deposited with the single rotating fixturing comprise only cubic CrN phase while the ones deposited with the stationary fixturing contain a mixture of hexagonal Cr2N and cubic CrN phases. By the increasing grain size of the Cr cathode, the droplet density of the Cr-N coatings increase somewhat while the hardness decreases for the Cr-N coatings deposited with stationary fixturing at 2 Pa nitrogen pressure.
Place, publisher, year, edition, pages
2014. Vol. 32, no 2, 021515- p.
Cathodic arc deposition, cathode surface evolution, substrate fixturing, wormlike ditches, grain size
IdentifiersURN: urn:nbn:se:liu:diva-96789DOI: 10.1116/1.4865923ISI: 000335964200056OAI: oai:DiVA.org:liu-96789DiVA: diva2:643345