Superelastic fullerene-like carbon nitride coatings synthesised by reactive unbalanced magnetron sputtering
2003 (English)In: Surface Engineering, ISSN 0267-0844, Vol. 19, no 4, 299-303 p.Article in journal (Refereed) Published
The present paper presents the results of in depth process characterisation and microstructural investigation of fullerene-like carbon nitride (FL - CNx) coatings combined with deformation analysis, such as indentation testing, in order to assess its performance. Unbalanced reactive magnetron sputtering of graphite in a nitrogen containing atmosphere is essential for the growth of FL - CNx structures chic to CxNy molecules, which are preformed in the process and may act as precursors or growth templates. The deposition process is best described as a hybrid of plasma vapour deposition and chemical vapour deposition. The fullerene-like (FL) structure leads to extraordinary mechanical properties which are assessed by nanoindentation. It exhibits a low work of indentation (usually a property associated with superhard materials) and also a low to moderate resistance to penetration. Therefore, deformation energy is predominantly stored elastically and released after unload giving it a tough and resilient character. In addition, the relatively low modulus leads to a spreading of the contact stresses over a larger volume and consequently to low, stress gradients at the substratelfilm interface. This hinders substratelfilm delamination under load and therefore results in a high load bearing capability, while the coating asperities behave elastically with 110 tendency to brittle fracture in tribological contact. This characteristic combined with the low coefficient of fraction reveals a coating which may be suitable for many tribological applications. (C) 2003 IoM Communications Ltd. Published by Maney for the Institute of Materials, Minerals and Mining.
Place, publisher, year, edition, pages
2003. Vol. 19, no 4, 299-303 p.
Engineering and Technology
IdentifiersURN: urn:nbn:se:liu:diva-47748DOI: 10.1179/026708403225007437OAI: oai:DiVA.org:liu-47748DiVA: diva2:268644