A thin calcium sodium hydroxypolyphosphate film on titanium alloy substrate was deposited by an argon ion beam with 60keV energy. X-ray diffraction (XRD)

Fourier transform infrared spectroscopy (FTIRS) and X-ray photoelectron spectroscopy (XPS) were used to characterize the as-deposited film. These analyses revealed that the as-deposited film was amorphous or no apparent crystallinity and each other diffusion between film and substrate was quite obvious. Contaminations from carbon and oxygen appeared during the deposition process. At the same time

a CO32- group was introduced into the as-deposited film. Ca-P ratio in the film was decreased with the increase of the assisting ion dose and the dissolubility resistance in the salt solution was increased with the increase of the assisting dose. In the experiment

we observed also that the electrochemical properties of the films in the Hanks solution exhibited an obvious difference before and after annealing. The film presented a high passivity all the time before the annealing

a polarization current expressing dissolubility increased only from 1 μA to 2μA when an electrode potential went up from 0 to 1500mV

while after annealing in an argon atmosphere at 600℃

polarization current was quite small (<0.5μA)

the dissolubility resistance was obviously superior to the former when the electrode potential ≤ 200mV. Its dissolubility was almost the same as that before annealing

however

when the potential was between 400mV and 800mV. When the electrode potential >800mV

the electrochemical properties became quickly poor and the polarization current was rapidly increased.