黄铜在含磷酸二氢钠或硅酸钠的铝酸盐电解液中的等离子电解氧化行为和耐腐蚀性能（英文）

采用等离子电解氧化(PEO)技术对黄铜进行表面处理，研究其在铝酸盐电解液中分别加入NaH₂PO₄ (S1)和Na₂SiO₃(S2)添加剂对涂层形成和耐腐蚀性能的影响。在S1电解液中进行PEO处理的初始阶段，黄铜表面形成AlPO₄和Al₂O₃的混合涂层，导致快速产生等离子体火花放电现象并形成由Al₂O₃、CuO、Cu₂O和ZnO组成的黑色涂层。然而，在S2电解液中，等离子体火花放电行为延迟产生。由于产生较多的Cu₂O,S2涂层显示为深红棕色。Mott-Schottky测试表明，S1涂层为p型半导体；S2涂层具有n型和p型半导体可调性。动电位极化和电化学阻抗谱(EIS)测试表明，PEO处理能显著提高黄铜的耐腐蚀性，腐蚀防护效率可达91.50%,S1涂层电荷转移电阻最大可达59.95 kΩ·cm²。

Plasma electrolytic oxidation behavior and corrosion resistance of brass in aluminate electrolyte containing NaH2PO4 or Na2SiO3

Plasma electrolytic oxidation (PEO) of brass was carried out in aluminate electrolytes with the addition of NaH₂PO₄ (S1) and Na₂SiO₃ (S2), respectively, with the aim to investigate the effect of additives on the coating formation and corrosion resistance. For the PEO in S1 electrolyte, a mixed layer of AlPO₄ and Al₂O₃ is formed at the initial stage, which leads to fast plasma discharges and formation of black coatings with the compositions of Al₂O₃, CuO, Cu₂O and ZnO. However, in S2 electrolyte, plasma discharges are delayed and the coatings show a reddish color due to more Cu₂O. Mott-Schottky tests show that the S1 coatings are p-type semiconductors; while the S2 coatings can be adjusted between n-type and p-type. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests show that the PEO treatment can significantly improve the corrosion resistance of brass, with protection efficiency up to 91.50% and the largest charge transfer resistance of 59.95 kΩ·cm² for the S1 coating.