Effect of current mode on PEO treatment of magnesium in Ca- and P-containing electrolyte and resulting coatings
发布时间：2021-07-12
点击次数：
影响因子：6.707
DOI码：10.1016/j.apsusc.2014.08.035
发表刊物：Applied Surface Science
关键字：Plasma electrolytic oxidation (PEO) coatings were produced on commercially pure magnesium in a biologically friendly electrolyte composed of 2 g L-1 Ca(OH)(2) and 12 g L-1 Na3PO4 center dot 12H(2)O using pulsed unipolarand bipolar current regimes with negative biasing varying from 0 to 20 mA cm(-2). Analysis of voltage transients was performed to characterise the PEO processes. The coating morphology and phase composition were studied by scanning electron microscopy and X-ray diffraction technique, respectively. In vitro corrosion performance of the coatings was evaluated in a simulated body fluid at 37 +/- 1 degrees C, using electrochemical techniques including open circuit potential monitoring, electrochemical impedance spectroscopy and potentiodynamic polarisation scans. The influence of the negative biasing on the PEO process and resulting coating characteristics is discussed. Unlike generally recognised beneficial effects of the negative biasing in PEO treatments of some other metal-electrolyte systems, it was found that detrimental effects are induced to the coatings on cp-Mg produced in the studied electrolyte when the negative current amplitude increases, which may be attributed to hydrogen liberation at the coating/substrate interface during the negative biasing cycles. As a result, a deterioration of vitro corrosion performance was observed for the pulsed bipolar PEO coatings compared to those produced using the pulsed unipolar regime which provides better quality coatings
合写作者：Allan Matthews
第一作者：Yonghao Gao
论文类型：期刊论文
通讯作者：Aleksey Yerokhin
论文编号：WOS:000343329100076
学科门类：工学
一级学科：材料科学与工程
文献类型：J
卷号：316
页面范围：558-567
ISSN号：0169-4332
是否译文：否
发表时间：2014-10-15
收录刊物：SCI、EI