Could humicity affect the mechanical properties of carbon based coatings?

0351434 - ÚPT 2011 RIV CZ eng J - Journal Article
Sobota, Jaroslav - Grossman, Jan - Vyskočil, J. - Novák, R. - Fořt, Tomáš - Vítů, T. - Dupák, Libor
Could humicity affect the mechanical properties of carbon based coatings?
Chemické listy. Roč. 104, č. 15 (2010), s. 375-377. ISSN 0009-2770. E-ISSN 1213-7103
Institutional research plan: CEZ:AV0Z20650511
Keywords : carbon * mechanical properties * humidity * fracture toughness of hard thin coatings
Subject RIV: JI - Composite Materials
Impact factor: 0.620, year: 2010

We evaluated the influence of humidity on tribological behaviour, impact resistance and tribological behaviour at elevated temperatures of carbon-based hard composite coatings deposited by PACVD with an interface metallic layer prepared by unbalanced magnetron sputtering. Impact tests were carried out at a relative humidity of 2.5% and 95% at an impact force of 600 N. Comparing measured values of crater volumes we can see, that the relative humidity substantially influences dynamic resistance of the coating - substrate system, in particular in the region of mechanical erosion of the coating. It is well known for years, that humidity can significantly influence the tribological behaviour of carbon-based coatings. However, humidity also influences the impact resistance of this type of films. By increasing the relative humidity, the value of dynamic impact resistance significantly increases. Simultaneously the wear rate of the coated part increases by many orders of magnitude.
Permanent Link: http://hdl.handle.net/11104/0191191