Projects / Programmes
PVD coatings as an alternative for corrosion protection of Fe and Al alloys
| Code |
Science |
Field |
Subfield |
| 2.04.00 |
Engineering sciences and technologies |
Materials science and technology |
|
| Code |
Science |
Field |
| T155 |
Technological sciences |
Coatings and surface treatment |
PVD, nanostructural hard coatings, corrosion, defect
Researchers (8)
| no. |
Code |
Name and surname |
Research area |
Role |
Period |
No. of publicationsNo. of publications |
| 1. |
18271 |
PhD Miha Čekada |
Materials science and technology |
Researcher |
2007 - 2010 |
446 |
| 2. |
15601 |
Jožko Fišer |
|
Technical associate |
2007 - 2010 |
12 |
| 3. |
27919 |
Barbara Kapun |
Chemistry |
Technical associate |
2008 - 2010 |
93 |
| 4. |
12616 |
PhD Darinka Kek Merl |
Materials science and technology |
Head |
2007 - 2010 |
129 |
| 5. |
22315 |
PhD Tadeja Kosec |
Chemistry |
Researcher |
2007 - 2008 |
343 |
| 6. |
01290 |
PhD Ingrid Milošev |
Chemistry |
Researcher |
2007 - 2010 |
719 |
| 7. |
26463 |
PhD Matjaž Panjan |
Electronic components and technologies |
Junior researcher |
2007 - 2010 |
231 |
| 8. |
09090 |
PhD Peter Panjan |
Materials science and technology |
Researcher |
2007 - 2009 |
793 |
Organisations (1)
| no. |
Code |
Research organisation |
City |
Registration number |
No. of publicationsNo. of publications |
| 1. |
0106 |
Jožef Stefan Institute |
Ljubljana |
5051606000 |
91,448 |
Abstract
PVD hard coatings, based on ceramic materials (nitrides, oxides, carbides) are prepared by vaccum depostion techniques and they are, in many cases, promissing alteranitves to galvanic protective coatings. Their wear resistance is excellent. However, corrosion resistance of such thin coatings often presents problems due to defects known as "pin- holes". These defects – when going through from the top surface to the coating/substarte interface - can result in a markedly decreased corrosion resistance of the coating/substrate system, if a less noble substrate material is coated with a more noble material like hard nitrides. Hence, the corrosion resistance of the coating/substrate system can be improved by "densifying" the morphology of the coatings. It has been suggested that the corrosion performance of PVD coated metal systems is strongly related to the microstructural characteristics.
Therefore, the first part of the project is to prepare multilayer nanostructured ceramic coatings of (TiAlN, CrN, TiAlN/CrN on Fe alloys, while some new coatings such as W-Al, and Cr-Al will be prepared on Al based substrates.
The deposition parameters (substrate temperature, plasma current density, partial pressure of reactive gas nitrogen) will be varied in order to prepare the structure with different density (from columnar to nanocrystaline). Properties such as hardness, adhesion and density will be determined for each coatings. Special attention will be devoted to the surface defect. Attempt will be made to find out the correlation between deposition parameters, surface pre-tretment and cleaning system with the number and size of the defects. Measurements related to the surface characterisation will be performed by SEM, TEM, AFM, XRD and XPS.
In addition, the electrochemical characterisation of the coating will be preformed. Electrochemical impedance measurement, galvanostatic and potentiostatic corrosion studies will be applied. From the electrochemical measurement the quantitative evaluation of the porosity of all coatings will be evaluated.
Significance for science
We have shown that the PVD processes are the excellent technique for alloys that can not be prepared by equilibrium processes. In this way we get an alloy of two or more materials with a different melting temperature, in our case, aluminium-tungsten or aluminium tantalum. The properties of such alloys may be very different from properties of the equilibrium alloys.
The microstructure plays important role. Microstructure investigation of nanocrystalline hard coatings were connected with the electrochemical investigations. The research field of corrosion investigation of technological materials covered with the noble hard coatings present interdisciplinary line; that can connect the basic knowledge of electrochemistry, surface physics, surface diagnostic, metallurgy, tribology and surface plasma technologies.
The research from all three years contributed to basic understanding of the hard coating behaviour. This is the key for successfully replacement galvanic coating with the environmental friendly coatings
Significance for the country
Electrochemical coating processes are widely used in Slovenian machine -and Electro-industry. Due to strictly environmental regulations of European Commissions, this industry will have to replace galvanic coating with the dry deposition processes. Physical vapour deposition-PVD are promising alternative. Metal, alloys and ceramics coatings can be made by PVD deposition processes. With this topic we were successfully co-operating with the PHOS - Orodja, Stroji in tabletiranje, Secovlje and we are planning to invite the other Slovenian industry using galvanic coating in their production.
Project results showed that the PVD processes cab be successfully applied for the protection of aluminum alloys.
Most important scientific results
Annual report
2008,
2009,
final report,
complete report on dLib.si
Most important socioeconomically and culturally relevant results
Annual report
2008,
2009,
final report,
complete report on dLib.si
