摘要
化学镀镍层具有优异的耐蚀性能,已广泛应用于各工业部门。七十年代前期,美国海军研究所的Pearlstein和Weightman把电镀双层镍原理应用于化学镀.发现双层化学镀镍层的耐蚀性比单层更好。以后,陆续有一些专利和文献报道了一些新的镀层组合体系。然而,有关双层化学镀镍技术的研究还不多。本工作着重研究一个新的组合体系:Ni-P(底层)+Ni-Mo-P(表层)的耐蚀性能并探讨其耐蚀机理。
The corrosion resistance and anti-corrosion mechanism of the double-layer electroless Nickel alloy deposit system, Ni-P (7. 5μm, outer)+Ni-Mo-P(2. 5μm, inner), were studied. The results of immersion corrosion test and neutral salt spray test showed that in so far as corrosion resistance is concerned, the double-layer deposit was much better than the single-layer (Ni-P or Ni-Mo-P) deposits of the same thickness and that it was better than the single-layer deposit of twice the total thickness. After heat treatment above 400℃, the corrosion resistance is further improved. AES surface analysis and depth profile technique,x-ray diffraction analysis technique,electrochemical tests and metallographic techniques were employed to investigate the anti-corrosion mechanism of this system. The results showed that the outer layer served as a sacrificial anode to provide electrochemical protection to the inner layer when the double-layer deposit was heat treated below 400℃ (including untreated condition),and that the protective effects were due to the changes of structure of system and had higher anti-corrosion performance when heat treated above 400℃.
出处
《中国腐蚀与防护学报》
CAS
CSCD
1991年第2期169-174,共6页
Journal of Chinese Society For Corrosion and Protection
