The Improvement of Corrosion Resistant for the Cf/Al Composites by Ni-P Coatings
Improved corrosion resistance of carbon fiber reinforced aluminum (Cf/Al) matrix composites can be achieved by applying appropriate coatings, and the electroless plating nickel-phosphor (Ni-P) coatings on the Cf/Al composites was provided in this paper. It has been founded that the pretreatment with zinc dipping solution for the electroless plating Ni-P can be approved perfect coatings on the Cf/Al composites. The EDS lines scanning results that the length of Ni-P coating is about 12 +m. In zinc dipping bath, matrix Al alloy surface could catch hold of action points for depositing Ni-P with substitution reaction, however, carbon fibers surface only have adsorption action points from zinc dipping bath, then, Ni-P alloys could deposit on the Al surface or carbon fibers. The uncoated and coated composites samples immersed in 3.5 wt % NaCl solution to contrast. The pitting corrosion behavior of the uncoated composites destroyed materials, therefore, the coated sample appeared pitting only on the surface. The corrosion resistance mechanisms of Ni-P coatings came from inhabiting the formation of the classical galvanic corrosion, additionally, the Ni-P coating was amorphous structure, there was not grains boundary which is sensitive for the corrosion reaction, so the corrosion resistant of Cf/Al composites were improved.
Yu Zhou, Shan-Tung Tu and Xishan Xie
C. Y. Wang et al., "The Improvement of Corrosion Resistant for the Cf/Al Composites by Ni-P Coatings", Key Engineering Materials, Vols. 353-358, pp. 1675-1678, 2007