Zr-8.8Al合金化学镀前磷化处理工艺研究

Phosphating pre-plating process for electro-less plating on Zr-8.8Al alloy

摘要:

前处理工艺的选择直接决定了化学镀Ni-P镀层质量的高低。本文采用磷化法对Zr-8.8Al合金进行了化学镀前处理，研究了Zr-8.8Al合金在不同磷化工艺获得的磷化膜以及化学镀Ni-P镀层显微结构、显微硬度、抗蚀性等的影响规律。结果表明，45℃下2min获得的磷化膜均匀致密；在此工艺下进行化学镀处理获得的Ni-P镀层为非晶结构，胞状结构，厚度达25μm。与裸材相比，Ni-P镀层显微硬度提高了60%，在3.5wt%NaCl溶液中自腐蚀电位发生正移，极化腐蚀后镀层胞状较完整，对Zr-8.8Al合金起到了较好的保护作用。

Abstract:

The quality of electro-less Ni-P plating is dependent on the process of pretreatment. In this paper, phosphating pretreatment was preformed for electro-less Ni-P plating on Zr-8.8Al alloy. The effect of phosphating process on the microstructure, microhardness and corrosion resistance in 3.5 wt% NaCl solution of electro-less Ni-P plating was investigated. The results show that the phosphating film obtained at 45℃ for 2min was uniform and even. The electro-less Ni-P plating has amorphous cellular structure and was about 25μm thickness. Compared with that of nonplated alloy, the microhardness of electroless Ni-P plating after phosphating pretreatment was improved by 60 percent. The corrosion potential of electro-less Ni-P plating after phosphating pretreatment in 3.5 wt% NaCl solution shift positively. The plating after corrosion is still complete, which shows that the corrosion resistance of electroless Ni-P plating after phosphating pretreatment is excellent.