电沉积工艺参数对纳米晶镍层显微硬度及沉积速率的影响

The Influence of Electrodeposition Parameters on Microhardness and Deposition Rate of Nanocrystalline Ni Coatings

采用脉冲电沉积法制备纳米晶镍层,利用高分辨透射电镜和显微硬度计对其微观结构和显微硬度进行了表征分析.结果表明:随电流密度和糖精钠含量的提高,纳米晶镍的显微硬度均呈现先增加后减小的趋势,当糖精钠含量为10 g/L,电流密度为10 A/dm2时达到最大值;显微硬度与平均晶粒尺寸的关系基本符合Hall-Petch方程;电沉积速率随电流密度的增加呈线性增长趋势,糖精钠的加入会提高沉积速率,但浓度的继续增加对沉积速率的影响不明显.

Nanocrystalline nickel（nc Ni） coatings were produced by adopting pulse current deposition method and their microstructure and microhardness were investigated through using a high resolution transmission electron microscopy and a microhardness tester.The results show that the microhardness of nanocrystalline nickel increases and then decreases as the current density and content of C7H4NO3SNa ·2H2O increase.At the same time,the microhardness reaches maximum when the content of C7H4NO3SNa ·2H2O is 10 g/L and the current density 10 A/dm2.It proves that the relationship between microhardness and mean grain sizes approximately is consistent with the Hall-Petch function.And the electrodeposition rate increases as the current density rises;the addition of C7H4NO3SNa ·2H2O results in the increase in deposition rate,but the continued increase in density has minimal effects on deposition rate.