采用表面分形维数评价Ni-P化学镀层的耐蚀性

摘要

Ni-P coatings were formed on RB400 steel to improve its corrosion resistance via electroless plating.Heat treatments were then conducted on the obtained coatings under different temperatures.Matlab software was applied to calculate surface fractal dimensions and evaluate the relation between the surface fractal dimension and the corrosion resistance of the Ni-P coatings.The results show that the surface fractal dimension values increased at first and then decreased with rising heat treatment temperature.The maximum average value was obtained at 350 ℃.However,the corrosion test results indicate that the best corrosion resistance of the treated coatings was achieved at 400 ℃.There was a positive correlation between the surface fractal dimension and the corrosion resistance.Therefore,it is feasible to realize the quantitative analysis and prediction the corrosion resistance of Ni-P coatings via comparing the surface fractal dimensions.%采用化学镀Ni-P镀层改善RB400钢的耐蚀性,并对镀层进行不同温度的热处理.通过Matlab计算其分形维数,并研究其表面分形维数与耐蚀性的对应关系.结果表明:随着Ni-P合金层热处理温度的升高,分形维数先增大后减小,350℃热处理镀层的表面分形维数最大.而镀层的耐蚀性能在400℃较好,分形维数的变化与镀层的耐蚀性能呈现一定的正相关关系,通过镀层表面形貌分形维数的变化可以较好地预测其耐蚀性.