Effect of fetal calf serum on the corrosion behaviour of magnesium alloys
Effect of fetal calf serum on the corrosion behaviour of magnesium alloys
复制标题
DOI：
10.1016/j.mseb.2011.07.018
复制
发表时间：
2011-12-15
影响因子：
3.6
通讯作者：
Mueller, W. -D.
中科院分区：
文献类型：
--
作者：
Hornberger, H.;Witte, F.;Mueller, W. -D.
采用微型电池系统研究了WE43镁合金的腐蚀行为。采用伏安法和阻抗谱法研究了工作电极微观结构的影响和电解质中蛋白质的影响。生产了两种类型的合金样品(i)通过永久模铸造和（ii）通过气体雾化然后挤压。结果表明，显微组织受生产工艺的影响较大。与铸造样品相比，挤压样品的相分布均匀性得到了改善。由于均匀性的提高，人们期望它具有更高的耐腐蚀性。然而，电化学结果是相互矛盾的，表明在挤压的微观结构中存在额外的相。利用能量色散x射线能谱（EDX）分析，挤压样品的二次镁稀土（RE）相的组成与铸造样品不同，并且存在额外的氧化相。在有和没有胎牛血清（FCS）的细胞培养基中对样品进行电化学研究后，由于极化曲线的长度，在伏安法中检测到FCS的影响。由于与工作电极接触的微型电池的尖端很小，显影气体容易在工作电极上扩散，破坏液体与对电极的接触，从而导致电流流动中断。当电压升高时，这种效果更加明显，当使用FCS电解质时，这种效果会降低。FCS的阻抗谱有轻微的变形，可以看作是动力学效应，而不是基本的不同腐蚀反应。微型电池系统提供了对FCS效果的深入了解，因为该系统能够收集整个系列的测量结果。与两个单次测量相比，这些序列反映了FCS引起的轻微差异。电化学腐蚀研究的重点放在浸液的前半小时。(C) 2011 Elsevier B.V.版权所有
The corrosion behaviour of WE43 magnesium alloys using the mini cell system was studied. Voltammetry and impedance spectroscopy were applied to study on the one hand the effect of microstructure of the working electrode and on the other hand the effect of proteins in the electrolyte. Two types of alloy samples were produced (i) by permanent mould casting and (ii) by gas atomization followed by extrusion. The results showed that the microstructure was strongly influenced by the production process. The extruded samples showed an improved homogeneity of phase distribution compared with cast samples as it was aimed for. Due to increased homogeneity it was expected to find higher corrosion resistance. However, the electrochemical results are contradictory and suggest an additional phase in the extruded microstructure. Using energy dispersive X-ray spectroscopy (EDX) the secondary magnesium rare earths (RE) phase of extruded samples showed differing composition than of cast samples as well as additional oxide phases. After the samples were electrochemically investigated in cell medium with and without fetal calf serum (FCS), an impact of FCS was detected in voltammetry due to the length of the polarisation curve. As the tip of the mini cell in contact with the working electrode is small, developing gases tend to spread on the working electrode and break the contact of liquid to the counter electrode: which results in disrupting the current flow. This effect was more pronounced when rising the voltage and was found reduced when using electrolytes with FCS. Impedance spectra were slightly deformed by FCS, seen as a kinetic effect but not as a basic differing corrosion reaction. The insight into the effects of FCS was provided by the mini cell system as this system enables to collect entire series of measurements. In contrast of two single measurements, those series reflected the slight difference caused by FCS. The focus of the electrochemical corrosion study was set on the first half hour of immersion. (C) 2011 Elsevier B.V. All rights reserved.