Abstract Electroless nickel plating on AZ91D substrate with a new and eco-friendly pretreatment process based on tuning an electrochemical homogeneous surface was investigated. The morphology, deposition process, chemical composition and microstructure of Ni–P coating were studied. It is indicated that β phases are selectively removed, producing a microstructural homogeneous surface and the subsequent uniform and compact Zn immersion layer. A defect-free and well adhesive Ni–P coating can be successfully obtained due to its uniform nucleation and growth based on such pretreatment. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests reveal that Ni–P coating could significantly improve the corrosion resistance of AZ91D substrate.

中文翻译：

---

AZ91D镁合金的均质化预处理和化学镀Ni-P

摘要研究了基于调整电化学均匀表面的新型环保预处理工艺对AZ91D基底进行化学镀镍。研究了Ni-P涂层的形貌，沉积过程，化学成分和微观结构。结果表明，有选择地去除了β相，产生了微结构均匀的表面和随后的均匀致密的Zn浸没层。基于这种预处理，由于其均匀的成核和生长，可以成功获得无缺陷且粘合性良好的Ni-P涂层。电位动力学极化和电化学阻抗谱（EIS）测试表明，Ni-P涂层可以显着提高AZ91D基板的耐腐蚀性。