Surface modification of Ti 13Nb 13Zr by plasma electrolytic oxidation
Surface modification of Ti 13Nb 13Zr by plasma electrolytic oxidation
复制标题
DOI：
10.1016/j.surfcoat.2017.12.022
复制
发表时间：
2018-02-15
影响因子：
5.4
通讯作者：
Fuerbeth, W.
中科院分区：
文献类型：
--
作者：
Lederer, S.;Lutz, P.;Fuerbeth, W.
在含有1 M H2SO 4 + 0.1 M H3 PO 4的电解液中，通过单极脉冲直流等离子体电解氧化（PEO）工艺在Ti 13 Zr 13 Nb上制备二氧化钛涂层。样品在63 C cm（-2）的恒定电荷载流子密度和从14 mA cm（-2）到700 mA cm（-2）的电流密度下进行恒电流阳极化。进行恒定电流模式和占空比为50%且频率为1 Hz至50 Hz的单极脉冲模式。采用扫描电子显微镜（SEM/EDX）、X射线衍射（XRD）和纳米压痕仪对表面层进行了表征。可以生成具有几微米厚度和多孔结构的氧化钛涂层。对涂层的形貌进行了评价。可以表明，孔隙率可以随着频率的增加而减小。涂层由金红石和金红石组成，涂层的相组成可以通过PEO电流密度来调节。通过开路电位测量、动电位极化和电化学阻抗谱（EIS）在添加0.1 M H2 O2的模拟体液（SBF）中测试了层的耐腐蚀性。EIS数据拟合表明，外多孔层和内阻挡层的复合层结构。在PEO过程中，较高的电流密度形成较厚的涂层，从而导致较低的腐蚀电流。与未处理样品（4.1GPa）和没有颗粒添加的PEO样品（8.5GPa）相比，将氧化锆纳米颗粒添加到电解质中将表面硬度增加到12.8GPa的平均值。
Titania coatings were produced on Ti 13Zr 13Nb by a unipolar pulsed DC plasma electrolytic oxidation (PEO) process in an electrolyte containing 1 M H2SO4 + 0.1 M H3PO4. The samples were galvanostatically anodized under a constant charge-carrier density of 63 C cm(-2) and current-densities reaching from 14 mA cm(-2) up to 700 mA cm(-2). Both a constant current mode and a unipolar pulsed mode with a duty-cycle of 50% and frequencies of 1 Hz to 50 Hz were performed. The surface layers were characterized by scanning electron microscopy (SEM/EDX), X-ray diffraction (XRD) and nanoindentation. Titanium oxide coatings with a thickness of several micrometers and a porous structure could be generated. The coatings morphology was evaluated. It can be shown that the porosity can be reduced with increasing frequency. The coatings consist of anatase and rutile, the phase composition of the coatings can be adjusted by the PEO current density. The corrosion resistance of the layers was tested in a simulated body fluid (SBF) with the addition of 0.1 M H2O2 by open circuit potential measurements, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). EIS data fitting indicates a composed layer structure of an outer porous layer and an inner barrier layer. Higher current densities during the PEO process formed thicker coatings, which consequently resulted in lower corrosion currents. The addition of zirconia nanoparticles into the electrolyte increased the surface hardness to an average value of 12.8 GPa, compared to that of an untreated sample (4.1 GPa) and PEO samples without particle addition (8.5 GPa).