METHODS:Electrochemical methods were used to measure the self-corrosion potential (Ecorr), self-corrosion current density (Icorr) and polarization resistance (Rp) of three alloys .And the polarization curves of the three alloys were recorded too. Meanwhile,microstructural and phase diffraction was examined by Field Scanning Electromicroscopy (FSEM) and surface chemical analysis was performed by Energy Diffraction X-ray(EDX).
RESULTS: The Icorr of Co-Cr alloy was(0.49±0.099)A/cm2x10-3A/cm2, which was higher than that of Ni-Cr alloy (P<0.05) and Ni-Cr-Ti alloy (P<0.05). Rp of Co-Cr alloy was(2307.65±398.84)ƒ¶.cm2,which was higher than that of Ni-Cr alloy (P<0.05) and Ni-Cr-Ti alloy (P<0.05). The results of FSEM showed that the corrosion resistance of Co-Cr alloy was better than that of Ni-Cr and Ni-Cr-Ti alloy. The results of EDX indicated that released Ni of Ni-Cr and Ni、Ti of Ni-Cr-Ti alloy after test decreased obviously (P<0.05).
CONCLUSIONS:The corrosion resistance of Co-Cr alloy is higher than that of Ni-Cr and Ni-Cr-Ti alloy.