电镀Zn-Ni和化学镀Ni-P交替镀层的抗腐蚀性能

Corrosion Resistance of Alternate Coatings of Zn-Ni Electroplating and Electroless Ni-P Plating

为了提高铸钢基体的耐腐蚀、耐磨性能,通过在铸钢基体上沉积化学镀Ni P和电镀Zn Ni的交替镀层的方法获得了一系列多层镀层。考察了多层镀层的外观和在5%NaCl中的抗腐蚀性能。研究表明,化学镀Ni P在电镀Zn Ni层上的沉积以及在铸钢基体上沉积Zn Ni与Ni P的交替镀层是可行的;所有交替镀层的耐腐蚀性优于相同厚度的Ni P化学镀层;亚层厚度为1μm和2μm的交替镀层比相同厚度的Zn Ni单层镀层的耐腐蚀性更为可靠;镀层厚度相同且Ni P亚层的厚度超过0.5μm时,交替镀层的耐腐蚀性随着层数和Zn Ni亚层厚度的增加而增加,这主要是多层效应的结果;在长达1a的浸泡腐蚀试验期间,所有镀层的外观都是令人满意的,都没有出现鼓泡和剥裂现象。

Alternate coatings of ZnNi electroplating and electroless NiP plating were deposited on casting steel to increase corrosion and wear resistance. The appearance and corrosion resistance of coating in 5% NaCl solution were investigated. Results showed that it was possible for direct deposition of electroless NiP plating on ZnNi electroplating as well as alternate coatings of ZnNi and NiP plating on casting steel. The corrosion resistances of both alternate coatings were better than single electroless NiP plating with same thickness, and more reliable than single ZnNi electroplating while the thickness of different sublayer in multiple layer was 1 μm and 2 μm. For the thickness of NiP sublayer was more than 0.5 μm, the corrosion resistance of multiple layer with same total thickness increased with the number of sublayer and the thickness of ZnNi plating, which was attributed to the multiple layer effect. 