ADHESION OF ANODIC TITANIUM DIOXIDE COATINGS ON TITANIUM GRADES 5 ALLOYS

MARÍA L. VERA; MARIO R. ROSENBERGER; CARLOS E. SCHVEZOV; ALICIA E. ARES

Warrendale, PA, 15086-7537, USA.

Otro; TMS ANNUAL MEETING; 2015

THE MINERALS, METALS AND MATERIALS SOCIETY

In the present research microhardness and adhesion of thin coatings of TiO2 (40 nm to 140 nm) for construction of a new heart valve design are evaluated. Coatings were produced by anodic oxidation of Ti-6Al-4V, using H2SO4 as electrolyte at different voltages (20 V to 60 V), employing heat treatments of 1 h at 500 °C and 600 °C. The Vickers ultra-microhardness of the substrate-coating tribological system was measured. The adhesion of coatings was evaluated by scratch test with varying loads at rates of 2 N/mm and 4 N/mm up to 10 N and 20 N. Microhardness values increased with the temperature of heat treatments. The adhesion was dependent on the rates of increasing load. At larger rate a brittle behavior was found and the critical load decreased with heat treatment temperature. Likewise, in anodic coatings without heat treatments, of less hardness, the critical load of adherence increased with increasing the coating thickness.