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摘要
In this work, the mechanical properties and corrosion behavior of Mg-2Zn-0.2Mn-xNd with various Nd contents were investigated using correlative microscopy, electrochemical evaluations and immersion tests in a simulated body fluid (SBF). Additionally, the surface potential distributions and phase characteristics were detected using SEM, TEM, AFM/SKPFM and EPMA, and the film layer's adhesive features and localized corrosion mechanism were investigated by XRD, CLSM and EIS measurement. The results indicate that the corrosion initiates as a consequence of micro-galvanic coupling between the cathode phases such as the ellipsoid-like/strip shape of Mg75Zn20Nd5 with a nanoscale size and matrix. For a prolonged immersion time, the holes with different sizes and depths mutually interacted and were connected, which was observed at the dendrite arms and the surrounding the Nd-enriched phases. Both the immersion and electrochemical tests illustrated #2 (0.6% Nd) has the best corrosion performance, and exhibits a uniform corrosion morphology on the surface, which due to the dense and adhesive products could reduce the corrosion sensitivity and alleviate the current exchange density between the medium and the electrode. Moreover, a corrosion model was proposed to interpret the corrosion mechanism.
- 出版日期2018-1-5
- 单位北京科技大学
