Hits: 650705

Nanostructured films: interface and tribological properties

Master thesis project: students applied and experimental physics

The advantages in materials properties by decreasing the grain size down to the nanometric level can be most readily realized in thin films for various applications. The deposition of metastable phases either of high-temperature type or with extreme shifts far from stoichiometric chemical composition, led to unexpected phases, quasi-amorphous structures, nano-sized grains and nano-composite. Our recent efforts are focused on DLC-based nanocomposite coatings consisting of ceramic nanocrystallites embedded in amorphous carbon matrix (see Fig. 1), in which ultra-low friction is tailored with superior wear resistance, being two properties often difficult to achieve simultaneously. The nearly frictionless nature of the nanocomposite coatings can be partially interpreted in terms of phonon dissipation in a finite system (see also FrankenVrij, vol. 9(2) 2005, p. 5). On the other hand, the superior wear resistance is related to the self-lubricating effects of DLC matrix like a solid lubricant. However, there are still a lot of mysteries about the physical mechanisms such as the sp³-sp² transition of DLC matrix, its surface interaction with environmental gases, etc. We are looking for students who are interested to do their final Master project on this topic. You will gain firsthand experience on magnetron sputtering deposition and in depth knowledge on microscopic (SEM, TEM, AFM) characterization and tribological testing of the nanocomposite coatings.

p1

Fig.: (a) SEM micrograph showing the fractured cross-section of a TiC/a-C:H nanocomposite coating; (b) HR-TEM micrograph revealing its nanostructure composed of TiC nano particles circled in white and (c) coefficient of friction (CoF) versus laps graph of the coating pointing at a breakdown of the Coulomb friction law in nanocomposite coatings, that is to say, a lower CoF at faster sliding velocity.

Contact:
Dr. Yutao Pei, kamer gebouw 13.020, e-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it , tel 50-363 4344
Dr. David Vainchtein, kamer gebouw 13.022, e-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Prof.dr. J. Th. M. De Hosson, gebouw 13.041, e-mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it