中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 22 No. 7 July 2012 |
（1. Key Laboratory of Biomedical Information Engineering of Ministry of Education,
School of Life Science and Technology, Xi’an Jiaotong University, Xi’an 710049, China;
2. State Key Laboratory of Metastable Materials Science and Technology,
Yanshan University, Qinhuangdao 066004, China;
3. College of Medicine, Xi’an Jiaotong University, Xi’an 710061, China）
Abstract:Titania films with nano-sized pores were prepared on the NaOH-HCl pretreated NiTi alloy substrate by sol-gel method. A crack-free film is obtained for the sample with a dense inner layer and a porous outside layer (sample TC1+1). The X-ray diffraction shows that the titania films are composed of anatase, and a little Ni4Ti3 phase in the heat treated substrate is also detected. The X-ray photoelectron spectroscopy results indicate that the titania film completely covered the NiTi substrate for sample TC1+1. The sample TC1+1 is hydrophilic with a contact angle about 20°, and UV illumination treatment for 15 min further decreases the contact angle to (9.2±3.2)°. The potentiodynamic polarization test in 0.9% NaCl solution reveals a better corrosion resistance of sample TC1+1 than the polished NiTi sample.
Key words: NiTi alloy; titania; sol-gel method; hydrophilicity; corrosion resistance
