本文通过激光加工结合电化学腐蚀脱合金法,成功实现了纳米多孔涂层的制备.采用激光熔覆首先在45钢表面制备了成形良好、稀释率低的铜锰合金熔覆层,并通过快速重熔工艺实现了初始材料组织细化.研究表明,在不同的电解液下,铜锰合金的临界腐蚀电位出现了明显的偏移;在不同的腐蚀电流下,铜锰合金腐蚀后的形貌迥异.最终,通过选择性腐蚀成功实现了纳米多孔铜和纳米多孔锰涂层的制备,并利用电位-pH图对脱合金的选择性腐蚀进行了详细的理论解释.
The nanoporous metal is fabricated by means of hybrid laser processing in combination with electrochemical dealloying. Cu-Mn alloy coatings with fine shape, low dilute ratio and refined microstructure are fabricated on medium carbon steel by means of laser processing. Polarization curve indicates that the Cu-Mn alloy shows selective dissolution characteristics for different electrolytes. Nanoporous Cu and nanoporous Mn are fabricated with optimal electrochemically dealloying parameters. Nanoporous Cu has pore sizes rangeing from 30 to 50 nm, while the surface morphology of the porous Mn shows a ribbon-like structure with ultrahigh roughness factor up to 900. Finally, the potential-pH diagram is used to explain the mechanism of the dealloying.