Objective To evaluate the corrosion behavior of Ni-Cr alloy with electroplated Au film in artificial saliva with different pH, compared with Ni-Cr alloy and Au alloy. Methods The electrochemical corrosion behavior of Ni-Cr alloy with electroplated Au film was evaluated by potentiodynamic polarization curve in artificial saliva（pH5.0, 6.8, respectively） to determine the corrosion potential（Ecorr ） , self-corrosion current density（Icorr ） and polarization resistance（Rp）, as compared with Ni-Cr alloy and Au alloy. Microstructure and phase diffraction was
examined by field scanning electron microscope（FSEM）. Results The Icorr of three alloys in acid artificial saliva （pH5.0） was significantly higher than that in neutral artificial saliva（pH6.8）. Meanwhile, the Rp in acid artificial saliva（pH5.0） was lower than that in neutral artificial saliva（pH6.8）. The results of FSEM showed that the range of corrosion widened in acid artificial saliva on the surface of Ni -Cr alloy coating Au. Conclusion In acid medium, the corrosion resistance of three kinds of alloys decrease to a certain extent.
