Chen Yanfei, Song Xiaocun, Zhou Jixue, Liu Hongtao, Yang Yuansheng
Advanced Materials Institute, Shandong Academy of Sciences, Jinan 250014, China.
Shandong Engineering Research Center for Lightweight Automobiles Magnesium Alloys, Jinan 250014, China.
Materials (Basel). 2018 Jan 2;11(1):63. doi: 10.3390/ma11010063.
Electrical connection of dissimilar metals will lead to galvanic corrosion. Therefore, overall surface treatment is necessary for the protection of dissimilar metal welded parts. However, serious unbalanced reactions may occur during overall surface treatment, which makes it difficult to prepare integral coating. In this paper, an overall ceramic coating was fabricated by plasma electrolytic oxidation to wrap the 6061-7075 welded part integrally. Moreover, the growth mechanism of the coating on different areas of the welded part was studied based on the dielectric breakdown theory. The reaction sequence of each area during the treatment was verified through specially designed dielectric breakdown tests. The results showed that the high impedance overall of ceramic coating can inhibit the galvanic corrosion of the 6061-7075 welded part effectively.
不同金属的电气连接会导致电偶腐蚀。因此，对异种金属焊接部件进行全面的表面处理是必要的。然而，在全面表面处理过程中可能会发生严重的不平衡反应，这使得制备整体涂层变得困难。本文通过等离子体电解氧化制备了一种整体陶瓷涂层，将6061 - 7075焊接部件整体包裹起来。此外，基于介质击穿理论研究了涂层在焊接部件不同区域的生长机制。通过专门设计的介质击穿试验验证了处理过程中各区域的反应顺序。结果表明，陶瓷涂层的高整体阻抗能够有效抑制6061 - 7075焊接部件的电偶腐蚀。
