目的 提高铝合金耐蚀性的同时，保证其良好的导电性。方法 通过化学镀的方法，在铝合金表面沉积一层镍磷合金。研究镀层厚度对试样导电性和耐蚀性的影响。通过电化学试验和浸泡试验，分析施镀前后的铝合金试样在模拟不同性质隧道渗水环境中的耐腐蚀性能。结果 当镍磷镀层厚度为11.6 μm时，镀层致密无孔隙，且表面胞状物分布均匀，试样具有最佳导电耐蚀综合性能。随着镀层厚度的增加，试样的体积电阻率随之增加。镀层厚度为11.6 μm时，试样实测体积电阻率为3.01×10–8 Ω?m。试样在3.5%NaCl溶液中的阻抗值随镀层厚度的增加，先增加后降低，镀层厚度为11.6 μm时，具有最佳的耐腐蚀性能。在pH=2、3.5%NaCl和pH=12的腐蚀介质中，化学镀镍磷后的试样自腐蚀电流密度相对于铝基体分别下降30%、60%和5个数量级。结论 厚度为11.6 μm的镍磷镀层可以赋予铝合金在各模拟环境中最佳的耐腐蚀性能，同时保障良好的导电性能。

The work aims to improve the corrosion resistance of aluminum alloys based on good electrical conductivity. A layer of Ni-P alloy was electroless plated on the surface of aluminum. The effects of coating thickness on the corrosion resistance and electrical conductivity of the samples were investigated. Corrosion resistance of aluminum alloys with and without Ni-P coatings in simulated tunnel seepage environment was analyzed by electrochemical test and immersion test. When the thickness of the electroless Ni-P coating was 11.6 μm, the coating was dense without pinholes and the surface was smooth, with uniform distribution of the cauliflower-like nodules and the sample had the best electrical and corrosion resistance. The resistivity of the sample increased as the coating thickness increased. When the thickness of the coating was 11.6 μm, the measured volume resistivity of the sample was 3.01×10–8 Ω?m. The impedance value of the sample in 3.5wt% NaCl solution increased first and then decreased with the increase of the thickness of the coating. The sample had the best corrosion resistance when the coating thickness was 11.6 μm. In the corrosion medium of pH=2, 3.5wt% NaCl and pH=12, the self-corrosion current density of the samples after electroless nickel plating was reduced by 30%, 60% and 5 orders of magnitude, respectively, relative to the aluminum matrix. The Ni-P coating with a thickness of 11.6 μm can give the aluminum alloy the best corrosion resistance in each simulated environment while ensuring good electrical conductivity.