Alumina coating formed on medical NiTi alloy by micro-arc oxidation

作者：Xu J L; Liu F; Wang F P^*; Zhao L C

来源：Materials Letters, 2008, 62(25): 4112-4114.

DOI：10.1016/j.matlet.2008.06.009

• NiTi alloy
• Al2O3 coating
• micro-arc oxidation
• corrosion resistance

Al(2)O(3) coatings were prepared on NiTi alloy by micro-arc oxidation in an aluminate solution. Thin-film X-ray diffraction (TF-XRD) indicated that the coating consisted of only Al(2)O(3) crystal phase. Energy dispersive X-ray spectrometer (EDS) showed that there was about 2.53 at.% Ni in the surface layer, which was greatly lower than that of NiTi substrate. Scanning electron microscopy (SEM) showed that the coating exhibited a typical porous surface and excellent adhesive interface between the coating and the substrate. Direct pull-off test showed that the coating had a mean coating-substrate bonding strength of 28 +/- 2 MPa. The results of electrochemical impedance spectroscopy (EIS) study and potentiodynamic polarization test indicated that the corrosion resistance of the coated sample was increased by two orders of magnitude compared with uncoated sample.

• 出版日期2008-9-30
• 单位哈尔滨工业大学