This contract focuses on the synthesis by
laser deposition of hard carbon films and their physico-chemical,
mechanical and tribological characterization. Diverse amorphous or
nanocrystaline structures with different sp3/sp2 ratio will be
obtained, by varying deposition parameters such as fluence, atmosphere,
pressure, substrate temperature, target-substrate separation distance.
All deposited films will be preliminary characterized in terms
hardness. The most interesting structures will be investigated by SEM,
AFM, XRD, XRR, XPS or Raman spectroscopy and mechanically in terms of
adherence, hardness, Young modulus, wear resistance and fretting. The
evolution of mechanical properties function of films structure will be
observed by tracing diagrams “deposition parameter/carbon
structure” and “hardness/structural parameter”. A
model that takes into account structural parameters of carbon films to
explain the evolution of mechanical properties will be developed.
Metallurgical cutting blades and piercing drills will be covered by PLD
with the best carbon films in terms of mechanical properties and
studied in real applications susceptible to wear and high temperatures.
The coatings will be subsequently studied for wear signs, cracks and
delamination. A microscopic comparison with uncoated or WC and ZrC
carbide coated standard tools will be performed. The final goal is to
obtain tools covered with carbon films by PLD superior in resistance to
commercially available solutions.
Fig.1 Cross-section visualization by SEM of a carbon thin film
synthesized by pulsed laser deposition
Fig.2 Nanostructuring of
the film by
laser irradiation for reducition of the friction coefficient