羧酸盐-尿素体系脉冲电沉积纳米晶铬镀层的工艺优化  

Optimization of the Technology for Electrodeposition of Nanocrystalline Cr Coating from Carboxylate-Urea System

作　　者：何新快[1,2] 

机构地区：[1]中南大学资源加工与生物工程学院,湖南长沙410083 [2]湖南工业大学包装与印刷学院,湖南株洲412008

出　　处：《材料保护》2009年第3期44-47,共4页Materials Protection

基　　金：中南大学博士后科学基金项目;湖南省自然科学基金项目(06JJ30021);湖南省教育厅科学研究项目(06C259)

摘　　要：六价铬电沉积工艺毒性高、污染大,三价铬电沉积工艺低毒、低污染,应用前景广阔。运用正交设计法优化了镀铬液配方,确定了其工艺参数,研究了影响脉冲电沉积纳米铬镀层质量的主要工艺因素,分析了镀液组成对铬镀层厚度和电流效率的影响,得到了羧酸盐-尿素体系脉冲电沉积纳米晶铬镀层的最佳工艺。结果表明:影响镀层厚度的主次因素分别是配位剂A(柠檬酸钠)、配位剂B(碳原子数不少于8的一元羧酸盐)和CrCl3.6H2O的浓度;影响电流效率的主次因素分别是配位剂A、CO(NH2)2和配位剂B的浓度。扫描电镜观察和电子能谱分析结果表明,铬镀层晶粒尺寸小于100nm,厚度均匀,表面光滑,结晶细致。该工艺能制备厚度为11.2μm的铬镀层,其电流效率高达25.32%。The technology for the electrodeposition of nanocrystalline Cr coatings from a carboxylate -urea bath and optimization of the bath composition were studied by making use of orthogonal design. The effects of the bath composition on the thickness of the coating and current efficiency were discussed. And the factors affecting the quality of the coatings were investigated. Results show that the thickness of the coatings was sequentially dependent on the con-centration of complexing agent A,complexing agent B,and CrCl3 ? 6H2O,while the current efficiency was related sequentially to the concentration of complexing agent A,CO( NH2 ) 2,and com-plexing agent B. The analyses by scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) show that the electrodeposited Cr coating had smooth and clean appearance and uniform thickness,with the grain size to be less than 100 run. It was feasible to prepare nanocrystalline Cr coating with a thickness of up to 11.2 μm under the optimum conditions,and the currentefficiency could be as much as 25.32%.

关 键 词：脉冲电沉积 三价铬 铬镀层 纳米晶 工艺优化 

分 类 号：TQ153.11[化学工程—电化学工业]