镍铬合金、钛合金及金铂合金在人工唾液中的耐腐蚀性能

目的：评价镍铬合金(Ni-Cr)、钛合金(Ti-6Al-4V)以及金铂合金(Au-Pt)在人工唾液中的耐腐蚀性能。方法：制作Ni-Cr、Ti-6Al-4V以及Au-Pt合金3种试件共9个，每种合金各3片。采用阳极极化技术，在37℃人工唾液中测定其稳态电位（Ecorr）,并记录其动电位极化曲线。用扫描电子显微镜观察试件表面形态变化，用X-射线衍射仪分析腐蚀试件表面产物的物相。结果：Ni-Cr、Ti-6Al-4V及Au-Pt合金的稳态电位分别为-115、-24和+61 mV。极化曲线表明，电位一定时(<600 mV),Au-Pt及Ti-6Al-4V合金的电流密度比Ni-Cr合金低。扫描电子显微镜观察表明，Ni-Cr合金试件表面有腐蚀痕迹，Ti-6Al-4V合金表面腐蚀痕迹不明显,Au-Pt合金表面无腐蚀痕迹。X-射线衍射图谱表明,Ni-Cr合金的腐蚀产物以Cr₂O₃为主,Ti-6Al-4V合金试件表面有TiO₂形成，Au-Pt合金表面无化合物生成。结论： 在人工唾液中， Au-Pt及Ti-6Al-4V合金均有较好的耐腐蚀性，Ni-Cr合金的耐腐蚀性相对较差。

Corrosion resistance of Ni-Cr, Ti-6Al-4V, and Au-Pt alloy in artificial saliva

Objective To evaluate the corrosion resistance of Ni-Cr alloy,Ti-6Al-4V alloy and Au-Pt alloy inartificial saliva.Methods Nine speci ments of Ni-Cr alloy,Ti-6Al-4V alloy and Au-Pt alloy were made and theywere divided into three groups(n=3).Then anodic polarization test was performed to measure the Ecorr andAnodic potentiondynamic polarization curves of each group.Surface changes of the alloys were observed by SEM.The products of corrosion were analyzed by X-ray diffractiometer.Results Ecorr of Ni-Cr alloy,Ti-6Al-4V alloyand Au-Pt alloy were-115,-24 and 61 mV.Anodic potentiondynamic polarization curves showed at the certainpotential(<600 mV),the Ti-6Al-4Vand Au-Pt alloys had lower current density than Ni-Cr alloy.SEMresultsshowed that the corrosive marks on the surface of Ni-Cr alloy were evident and that of Ti-6Al-4V were not veryevident.There were not corrosive marks on the surface of Au-Pt alloy.X-ray diffractogram showed that thecorrosive product was mainly Cr chemical compound on the surface of Ni-Cr alloy and Ti chemical compound on thesurface of Ti-6Al-4V alloy.The chemical compound in Au-Pt alloy was not detected.Conclusion In artificialsaliva,the corrosion resistance of Au-Pt alloy and Ti-6Al-4Valloy are superior to that of Ni-Cr alloy.