Nanocomposite Hard Coatings: Deposition Issues and Validation of their Mechanical Properties

Schwaller, Patrick; Haug, Franz-Josef; Michler, Johann; Patscheider, Jörg (2005). Nanocomposite Hard Coatings: Deposition Issues and Validation of their Mechanical Properties Advanced Engineering Materials, 7(5), pp. 318-322. Wiley-Blackwell - STM 10.1002/adem.200500045

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The limitations of conventional coatings due to inferior hardness or poor oxidation stability can be overcome by nanocomposite hard coatings such as nc‐TiN/a‐SiNx, which consists of nanocrystalline TiN and a non‐crystalline tissue phase of SiNx which are mutually immiscible. The properties of nanocomposite coatings, especially their increased hardness, can be explained by their nanostructure, which leads to a maximum hardness at typically 80 atomic percent of the crystalline phase. We show that enhanced hardness can only be attained when the silicon nitride phase is sufficiently nitrided. The accurate and reliable measurement of the hardness and elastic modulus requires the use of appropriate nanoindentation equipment and a careful tip correction with periodical validation. It is shown that for a correct hardness determination of a few microns thick nanocomposite coatings, an indentation depth of 100 nm is sufficient. The maximum hardness of our nc‐TiN/a‐SiNx coatings deposited by a hybrid UBM/arc‐PVD process is about 40 GPa. This value represents a global hardness value, due to the nanocomposite structure there may be a local hardness variation of about ±10 %.

Item Type:	Journal Article (Original Article)
Division/Institute:	School of Engineering and Computer Science > Institute for Surface Applied Laser, Phototonics and Surface Technologies ALPS School of Engineering and Computer Science
Name:	Schwaller, Patrick; Haug, Franz-Josef; Michler, Johann and Patscheider, Jörg
ISSN:	1438-1656
Publisher:	Wiley-Blackwell - STM
Language:	English
Submitter:	Patrick Schwaller
Date Deposited:	17 Dec 2019 12:26
Last Modified:	17 Dec 2019 12:26
Publisher DOI:	10.1002/adem.200500045
ARBOR DOI:	10.24451/arbor.9271
URI:	https://arbor.bfh.ch/id/eprint/9271