Etude de l'interaction entre le Zirconium en couche mince et un substrat en acier .

Abstract

Thin films of zirconium carbides and nitrides have been elaborated by depositing the zirconium films by RF magnetron sputtering on high carbon steel EN C100 (1 %wt. of carbon) and nitrided EN C100 steel substrates, followed by a thermal annealing of the (coatings/substrates) systems. By activing the interstitials atoms (carbone, nitrogen) diffusing from the substrate to the film, the thermal annealing leads to the formation of hard coatings with good adhesion to the substrate and excellent mechanical properties. The influence of annealing temperature on the microstructural and mechanical properties and on the formed compounds in the thin films is elucidated. The nitridation of substrates using a thermochemical technique by ionic plasma allows the formation of stœchiometric compound ZrN of the nitride, while only the under-stœchiometric compound ZrC0.6 of the carbide which is formed on the pristine substrate. The measured values of hardness and Young modulus are 28 GPa and 380 GPa for the nitride film against 18 GPa and 240 GPa respectively for the carbide film.