纳米TiO_2-Ni基镀层的电刷镀沉积行为研究

Deposition behavior of nano-TiO_2/Ni composite coating using brush plating

为了使纳米颗粒均匀地悬浮在镀液中从而获得纳米颗粒均匀分布的复合镀层,研究了不同表面活性剂对纳米TiO2在镀液中的分散行为的影响,采用电刷镀方法制备纳米TiO2-Ni基复合镀层,并运用SEM、EDS和XRD研究了纳米TiO2-Ni基镀层的表面形貌和成分特点。结果表明,阳离子型表面活性剂十六烷基三甲基氯化铵(CTAB)对纳米TiO2颗粒的分散效果最好,沉降时间超过40min;CTAB分散的纳米TiO2-Ni基镀层显微硬度比不加表面活性剂的提高50%左右,镀层结合性较好,孔隙率显著降低;CTAB分散的纳米TiO2-Ni基镀层均匀细致、晶粒细小,纳米TiO2被生长着的镍晶粒夹持嵌埋,分布于镍基间隙中,镀层由纳米TiO2颗粒和镍基组成。纳米粉末与镍共沉积符合迁移、吸附、嵌埋的过程。

In order to make evenly suspended in the electrobath as to obtain uniform distribution of nano-particles composite platings,in this article the influence of different surfactants on nano-TiO2 dispersion were studied. nano-TiO2/Ni composite coating was acquired by brush plating method,and the surface micstructure of nano- TiO2/Ni coating was obsereved by SEM and XRD. The result shows that cationic surfaetant has the best effect on dissipating nano-TiO2 in the solution,it doesn＇t deposit more than 40min,thus the agglomeration of nanopar- tieles is solved by CTAB to some degree;the hardness of nano-TiO2/Ni coating with cationic surfactant CTAB is improved 50 ~/4o compared with that without surfactant, besides the coating has a great combination properties and less porosity; cationic surfactant CTAB leads to fine and dense microstructure of the composite coating, where nanoparticles are distributed homogeneously in the nickel matrix and deposited along the boundaries of electro- deposited Ni grains, furthermore the coating is composed of nano-TiO2 and Ni. Thus,it is evident that codeposi- tion mechanics of nano-TiO2 and Ni should be motion, absorption and mechanics mechanism.