In situ formation of titania film on NiTi alloy treated with hydrogen peroxide solution at low temperature
(1. Department of Materials Science and Engineering, Southeast University,
Nanjing 210096, China;
2. Department of Physics and Materials Science, City University of Hong Kong,
Hong Kong, China;
3. School of Public Health, Southeast University, Nanjing 210096, China)
Nanjing 210096, China;
2. Department of Physics and Materials Science, City University of Hong Kong,
Hong Kong, China;
3. School of Public Health, Southeast University, Nanjing 210096, China)
Abstract: Chemically polished NiTi shape memory alloy(SMA) substrate was treated with a boiling aqueous solution containing hydrogen peroxide to form titania film in situ at low temperature. The surface characterizations of titania film on NiTi substrate were investigated by scanning electron microscopy, X-ray diffractometry and X-ray photoelectron spectroscopy. The results show that titania film is successfully fabricated in situ on NiTi SMA by this surface oxidation method. It is mainly composed of rutile and anatase, whose surface compositions and morphologies are sensitive to H2O2 content. In situ formation mechanism of titania film on NiTi substrate was discussed based on the experimental results.
Key words: titania; thin films; shape memory alloy(SMA); NiTi alloy; oxidation; surface structure