Gr/Al复合材料表面化学镀镍沉积特性及耐蚀性

DEPOSITION CHARACTERISTIC FOR ELECTROLESS PLATING NICKEL ON Gr/Al COMPOSITE SURFACE AND ITS CORROSION RESISTANCE

用化学镀镍法在Gr/Al复合材料表面沉积了Ni-P合金,研究其沉积特性及耐蚀性。结果表明,Gr/Al复合材料表面化学镀镍具有其特殊性:在前处理的活性质点形核时,基体铝合金从浸Zn溶液中置换出催化活性的Ni核;增强体石墨纤维可以吸附一定数量的Ni核,随后的化学镀镍时Ni-P合金就会在Gr/Al复合材料表面均匀沉积。表面化学镀镍通过阻挡腐蚀原电池反应中电偶腐蚀的导电路径以及形成非晶态的镀层结构,显著地提高了Gr/Al复合材料的耐蚀性,延长了使用寿命。

The deposition characteristic of electroless plating Ni-P on Gr/Al composite surface and coatings corrosion resistance are investigated for the particularity of Gr/Al composite surface in this paper. During forming nucleus of action points, chemical replacement reaction is taking place in the dipping zinc solution on the Al substrate, but nucleus of action points are adsorbed on the reinforcement graphite fibers surface. Al could be used of chemical replacement reaction to Ni nucleus in dipping Zn baths and graphite fibers only absorb active Ni nucleus from pertreatment solution. After formation of nucleus for depositing nickel, Ni-P alloys would deposit on the Gr/Al composite surface. It resulted that Ni-P coating blocked off the circuit for the electrochemical reaction in galvanic couples, and the non-crystal coatings had not sensitive grain boundary for the corrosion reaction, the corrosion resistance was improved by Ni-P coating. The Ni-P coatings could prolong the Gr/Al composites service time.