镍铬合金在人工唾液中的电化学腐蚀行为

Electrochemical corrosion characteristics of Ni-Cr alloy in artificial saliva

目的 本项研究旨在探讨镍铬合金在体外的电化学腐蚀行为。方法 实验应用极化曲线方法 ,将镍铬合金浸泡在人工唾液中 ,温度为 36 .5℃ ,pH值为 7.0 ,测量试样的腐蚀电位和自腐蚀电流密度。应用X射线光电子能谱 (X rayphotoelectronspectroscopy,XPS) ,分析试样表面的元素成分变化。结果 实验结果表明 ,镍铬合金的点蚀电位为 - 390mV ,钝化电位为 - 1 60mV ,活性溶解区从- 1 60mV到 - 2 70mV。它的自腐蚀电流密度为 0 .2 62 μAcm- 2 。极化曲线试验后 ,对试片表面进行XPS能谱分析 ,所得原子峰高图发现 ,随着氩离子刻蚀的由浅入深 ,金属元素镍 (Ni)、铬 (Cr)、钼(Mo)、铁 (Fe)的含量逐渐增加 ,而非金属元素氧 (O)、碳 (C)的含量则逐渐减少。由于钙 (Ca)为介质中的元素 ,其含量也呈逐渐减少。结论 镍铬合金在人工唾液中 ,经过电化学极化曲线试验 ,会发生腐蚀反应 ,生成腐蚀产物附着于试样表面目的 本项研究旨在探讨镍铬合金在体外的电化学腐蚀行为。方法 实验应用极化曲线方法 ,将镍铬合金浸泡在人工唾液中 ,温度为 36 .5℃ ,pH值为 7.0 ,测量试样的腐蚀电位和自腐蚀电流密度。应用X射线光电子能谱 (X rayphotoelectronspectroscopy,XPS) ,分析试样表面的元素成分变化。结果 实验结果表明 。

Objective The aim of this study is to determine the electrochemical corrosion characteristics of Ni Cr alloys in vitro. Methods The electrochemical corrosion behavior of Ni Cr alloys was studied by polarization curves in artificial saliva at 36.5℃ (pH=7.0) to measure the corrosion potential and self corrosion current density. With X ray photoelectron spectroscopy, the element content was analyzed. Results It was found that the dot corrosion voltage of Ni Cr was -390 mv, and passivation voltage -160 mv. The area of active dissolvation was from -160 mv to -270 mv. The self-corrosion current density is 0.262 μAcm -2 .From XPS, the content of Ni?Cr?Mo?Fe was increasing gradually, and the content of O?C was decreasing gradually. The content of Ca decreased because Ca existed in the artificial saliva. Conclusion After polarization curve test, Ni Cr alloy would occur corrosive reaction, and the corrosion product would attach to the surface of the material.