磷含量对化学镀Ni-P层抗垢性能与抗蚀性能的影响

Effect of Phosphorus Content on Anti-fouling and Anti-corrosion Properties of Electroless Ni-P Deposition

通过调整Ni-P化学镀工艺参数,获得了不同磷含量的镀层,具有非晶、纳米晶及二者混合的微观结构。进一步的污垢沉积实验表明,有Ni-P镀层的试样与没有镀层的碳钢试样相比,其污垢沉积速度均明显下降。同时Ni-P镀层的微观结构对抗垢性能的影响表现为,随镀层中纳米晶的增加,抗垢性能有减弱的趋势,非晶镀层表现出最佳的抗垢性能。电化学腐蚀结果也表明,非晶镀层的抗蚀性最好,随纳米晶的增加,腐蚀电位向低电位方向移动。微观结构对于抗蚀性的影响趋势与对抗垢性能的影响一致。抗垢性能与抗蚀性能有内在的联系,易于被腐蚀的镀层也容易通过"过渡层"的形成而易于污垢的附着。这为充分利用镀层的性能,将镀层应用于热交换器换热面的防垢抗蚀方面,奠定了一定的研究基础。

The electroless Ni-P deposits with different phosphorus contents were prepared by adjusting process parameters, in which amorphous, nanocrystalline phase and the mixture of both could be obtained. Crystallization fouling adhering experiments indicate that these electroless Ni-P deposits have better anti-fouling property than that of un-coated sample. The effect of microstructure on anti-fouling property of Ni-P deposits is that the amorphous deposit has the best anti-fouling property and the adhering amount of crystallization fouling increase with the increasing of nanocrystalline phase. Electrochemical corrosion experimental results showed that the anaorphous deposit had the best corrosion resistance and the corrosion potential for other deposits shifted to lower potential with the increase of nanocrystalline phase. The trend about the effect of microstructure on the anti-fouling property is consistent with that of corrosion resistance. Anti-fouling and corrosion resistance are intrinsically linked, that is, the easy eroded surface is also easily adhered by fouling through forming the ＂ transitional interface＂ which connects the fouling and surface of deposit. The present work is fundamental research for the anti-fouling and corrosion resistance technology applying in the heat exchangers.