Fullerene-like Carbon Nitride Coatings: From Lab-scale Research to Industrial-scale Production Prof. Esteban Broitman Prof. Esteban Broitman Thin Films Physics Division, IFM, Linköping University, Sweden
The interest on carbon nitrides Science 25 August 1989: Vol. 245. no. 4920, pp. 841 842 1694 citations
The interest on carbon nitrides 80 70 60 Frequency 50 40 30 20??? 10 0 1990 1995 2000 2005 2010 Publication Year Number of articles published with the keyword C 3 N 4 Source: ISI Web of Knowledge June 30 th, 2011
Amorphous Carbon Nitride Films C N At low C N, the N is incorporated in a graphite-like structure There is no more than 1 N per aromatic ring
Fullerene-like Carbon Nitride Films A-B-C:Plan-views D: Cross-section High Resolution Transmission Electron Microscopy E. Broitman, et al., Wear 248 (2001) 55-64
Fullerene-like Carbon Nitride Films Discovered in Linköping University (Sweden) in 1994 N C N causes bending of graphite by substituting for C sp 3 sp 2 N promotes the formation of cross linking -Bent and intersecting graphitic planes Broitman et al., Physical Review B 59 (1999) 5162
Fullerene-like Carbon Nitride Films Discovered in Linköping University (Sweden) in 1994 N C sp 3 sp 2 Nanoindentation Elastic Recovery ~ 95 %!!!
Laboratory Deposition Chamber Laura Linköping University (Sweden) Coating chamber (D x h) : 800 x 800 mm 2 magnetron sputter cathodes 75 mm diameter Accessibility: 1 load-lock 100 mm diameter
How to transfer the fullerene-like process to an industrial-size deposition chamber??? There are many technical challenges and obstacles!
Industrial Deposition Chamber SAMSON Linköping University (Sweden) Based in a: CC 800 /9 - CemeCon (Germany) Coating chamber (l x w x h) : 850 x 850 x 1000 mm 4 magnetron sputter cathodes, length: 500 mm Accessibility: 1 front door, 2 side doors
Differences Laboratory-scale Industrial-scale Maximum area size where the coating has uniform properties (related to cathode size) 50 mm diameter 500 x 50 mm
Magnet N + Ar + e - Ar + e - e- e - Ar + Ar + Ar + e - N + e - C Ar + N + CN C CN Target Substrate Laboratory-scale System Simple 1-fold rotation The sample is always in contact with the plasma
Industrial Chamber: multiple rotation for the parts to be coated The sample is not always in contact with the plasma Movie from an industrial CC 800 /9 chamber at CemeCon (Germany)
Differences Laboratory-scale Industrial-scale Base pressure (related to purity of the coating) ~1x 10-10 Torr ~1x 10-6 Torr Substrates Temperature Control Small mass to heat Precise Control In-situ measurement Big mass to heat Difficult to control Indirect measurement How important is the temperature?
How important is the temperature? Data Obtained in a Laboratory Deposition System E. Broitman et al, in Tribology of DLC Films, C.Donnet and A. Erdemir (Eds), Springer (2007) Chapter 24.
How important are the Plasma parameters? The plasma parameters influence the microstructure and chemistry of the deposited films It is necessary a correct characterization in order to transfer from the lab-scale to industrial-scale process Langmuir Plasma Probes
How important are the Plasma parameters? Data Obtained in a Laboratory Deposition System E. Broitman et al, in Tribology of DLC Films, C.Donnet and A. Erdemir (Eds), Springer (2007) Chapter 24.
Differences Laboratory-scale Industrial-scale Slow deposition rate Thin coatings (< 500 nm) for research purposes Good adhesion to Si substrates High deposition rate Thicker coatings (~1-5 µm) for industrial applications Bad adhesion to steel substrates Extra limitation in our transfer: The steel substrates cannot be heated at more than 200 o C!!!
Improvements about the adhesion on steel substrates at low tempeatures: Please, attend my talk: Adhesion Improvement of Carbon-Based Coatings through High Plasma Ionization Deposition Esteban Broitman, Lars Hultman Friday 25 th November at 12:00 Hs.
Results Laboratory-scale Industrial-scale Microstructure Plan-views High Resolution Transmission Electron Microscopy Fullerene-like structure 250 nm thick T s = 300 o C Fullerene-like structure (short range) 2500 nm thick T s = 180 o C
Results Laboratory-scale Industrial-scale Mechanical Properties 3 HT-CNx a-c LT-CNx Load [mn N] 2 1 0 0 20 40 60 80 100 120 140 Displacement [nm] Resiliant Material High Hardness and High Elasticity T s = 350 o C Resiliant Material High Hardness and High Elasticity T s = 180 o C
Conclusions & Future Work We have been able to transfer the process from labscale to industrial-scale systems We can deposit thick (1-3) µm fullerene-like CN x films on steel substrates at 180 o C in an industrial- size deposition system Our work open a huge window for new applications of fullerene-like CN x coatings
Acknowledgments Swedish Government Strategic Research Area Grant in Materials Science Lars Hultman, Grzegorz Greczynski & Susann Schmidt @ Linköping University Thank you!