Corrosion of galvanic couplings of Ni-Cr and Co-Cr alloys with Ti-6Al-4V in artificial saliva using electrochemical methods

ABSTRACT In this work, the open-circuit corrosion potentials of the alloys studied in aerated artificial saliva were determined; in the same solution, the potentiodynamic polarization curves of said alloys have been drawn. The corrosion potentials and current intensities of the galvanic coupling of the Ti-6Al-4V alloy with the Co-Cr and Ni-Cr alloys were determined using the Evans method, finding that the galvanic couples more resistant to corrosion in the electrolytic medium considered are those formed between the Ti alloy and the Co-Cr alloys; the least resistant are those formed between Ti alloy and Ni-Cr alloys. The corroded surfaces of the seven alloys considered in this work were also studied, and by EDAX the corrosion products due to the ions detached in the electrolytic medium were analyzed.

摘要 本研究测定了受试合金在充气人工唾液中的开路腐蚀电位；并在同一溶液中绘制了上述合金的动电位极化曲线。采用埃文斯法（Evans method）测定了Ti-6Al-4V合金分别与Co-Cr合金、Ni-Cr合金构成的电偶对的腐蚀电位与电流强度，结果表明：在所考察的电解介质中，耐蚀性能更优的电偶组合为Ti合金与Co-Cr合金形成的电偶，而耐蚀性最差的则为Ti合金与Ni-Cr合金构成的电偶。本研究还对本次考察的7种合金的腐蚀表面进行了分析，并通过能量色散X射线谱（EDAX, Energy Dispersive X-ray Analysis）对电解介质中脱附离子所生成的腐蚀产物进行了表征。