Alexander Ruden

Propiedades mecánicas y tribológicas de películas lubricantes de ws2 depositadas por medio de magnetrón sputtering dc no reactivo

wS2 thin films were deposited by using magnetron sputtering on 304 stainless steel substrates to observe material capabilities as a solid lubricant exposed to environments with relative humidity above 40%. Coatings obtained presented hexagonal crystalline structure with combined texture in the (100) and (101) planes, parallel to the c axis and linked to columnar detachment and the formation of a transference film. High ductility was observed from the hardness, elastic moduli, plasticity index, and critical load. Friction coefficients measured by ball-on-disc test with alumina balls showed data around 0.09. Increasing the load from 1 to 10 N improved coating friction behavior. Results show that tribo-oxidation phenomena promotes a transition of the wear mechanisms from adhesive to abrasive.

Análisis de corrosión y tribológico de capas delgadas metálicas de Ti y aleación titanio – circonio depositadas por DC magnetrón sputtering no reactivo sobre acero inoxidable de aplicación médica

Titanium (Ti) and titanium-zirconium (Ti-Zr) allow thin films were deposited on AISI 304 stainless steel substrates by non reactive PVD-DC Magnetron Sputtering technique in argon environment, using Ti 99,99% and Ti-Zr (70/30) targets. Corrosion and tribological measurements were performed. From the Potentiodynamic the corrosion and pitting potential for the substrates and thin films were obtained. Using NaCl 3,5% p/p electrolytic solution, a Hg/KCl electrode saturated at 37°C temperature (human corporal temperature). Results obtained shows that thin films increases pitting potential enhancing life time of the substrates. Through Ball on Disc system, coefficient of friction (COF) and wear rate were calculated for AISI 304, Ti and Ti-30Zr, presenting metallic tribological behavior. Morphological analysis of the wear track and corrosion pitting shape were performed by optical microscopy.