The effects of annealing temperature on the electrochemical properties of Zr

56

Cu

19

Ni

11

Al

9

Nb

5

metallic glass in 3.5% NaCl solution were investigated by differential scanning calorimetry（DSC）

X-ray diffraction（XRD）

scanning electron microscopy（SEM）

potentiodynamic polarization tests and electrochemical impedance spectroscopy（EIS）.DSC results show that at the heating rate of 10 K/min

the glass transition temperature Tgis689.0 Kand the crystallization temperature Txis 733.3 K.XRD and SEM results reveal that the as-cast sample and the samples annealed at 623 Kand 723 Kfor 30 min present amorphous structure and ones annealed at 823 K and 923 Kare crystallized with higher crystallization degree at higher annealing temperature.Potentiodynamic polarization tests and EIS show that for the as-cast samples and the samples annealed at 623～923 Kfor 30 min

with the increase of the annealing temperature

the spontaneous corrosion potential is increased firstly and then decreased

and the corrosion current density is decreased firstly and then increased

while the radius of capacitance impedance is increased firstly and then decreased.It is indicated that the corrosion resistance is increased firstly and then decreased

with the best for the sample annealed at 723 Kand the worst for the sample annealed at 923 K.