The adhesion and corrosion resistance of Ti-O films on CoCrMo alloy fabricated by high power pulsed magnetron sputtering (HPPMS)

In order to explore the potential application on cardiovascular stent, titanium oxide films were fabricated on CoCrMo alloy substrate by high power pulsed magnetron sputtering (HPPMS). The effect of Ti interlayer and thickness of Ti-O film on the film adhesion was investigated by the scratch test and tension test. After different tensile strain, the corrosion behavior of Ti-O coated CoCrMo alloy and bare CoCrMo alloy was also investigated by polarization tests. The results showed that the deposition of Ti interlayer can obviously improve the film adhesion and the film adhesion decreased with film thickness increase. In addition, the 30 nm Ti-O film with 10 nm Ti interlayer had excellent adhesion and it could withstand 30% relative elongation without obvious delamination. The corrosion resistance of Ti-O coated CoCrMo alloy was superior to bare CoCrMo alloy after different tensile strain. Due to its good adhesion and corrosion resistance after different tensile strain, the HPPMS Ti-O film had a potential application on CoCrMo alloy cardiovascular stent surface modification.