返回
Microscopic local elements in the phosphating process
DOI:10.1016/S0013-4686(03)00385-2.png)
摘要
En 中文
The addition of Ni2+ to the phosphating bath improves the corrosion stability as well as the adhesion of coating layers. This is caused by the formation of Ni deposits on the base of pores of the phosphate layer. They do not only catalyse the surface reactions but generate a more corrosion resistant surface as well. The deposition of Ni during the phosphating of electrogalvanised steel was studied in aqueous solutions by simultaneous measurement of the rest potential and electrode capacity in dependence on time, temperature and bath composition. The electrochemical response of the system was corroborated with SEM pictures, gravimetric measurements and X-ray fluorescence analysis. Rest potential patterns under different solution and initial surface conditions were interpreted by microscopic local elements. During the deposition of the phosphate layer, the cementation of Ni on the initially corroding Zn gives rise to the formation of surface Ni-Zn alloys, providing cathodic centres where the reduction of H+ and accelerators (NO2-, NO3-) is favoured. The process matches with a quasi-instantaneous displacement of the rest potential from that corresponding to the Zn/Zn2+ couple towards the corrosion potentials of cementated Ni-rich alloys. The appearance of a simultaneous characteristic capacity peak was analysed in terms of the surface changes due to Ni-cementation together with an increment of the growth rate of phosphate crystals and the formation of oxide films. Microscopic local Ni deposits have an extension of some micrometer and a thickness of few hundred nanometer up to 1 mum. (C) 2003 Elsevier Ltd. All rights reserved.
Keyword:
phosphating
Ni deposition
Zn-coated steels
local elements
AI总结
对已上传原文的论文进行重点信息的提取,主要内容包括:简要概述、研究摘要、背景介绍、关键亮点、图文解析、展望与总结。
期刊
IF:
5.6
论文数:
4.0W
被引数:
12.6W
机构
暂无机构信息
引用论文
Fibroblast growth factor 2 increases Otx2 expression in precursor cells from mammalian telencephalon
Cementation of Ni2+ ions from acidic sulfate solutions onto a rotating zinc disc酸性硫酸盐溶液中的Ni2离子在旋转的锌盘上的胶结
ELECTROCHIMICA ACTA
IF5.6
Corrosion and polarization characteristics of zinc in neutral—acid media — I. Pure zinc in solutions of various sodium salts锌在中性酸性介质中的腐蚀和极化特性-I.各种钠盐溶液中的纯锌
Inter‐rater Reliability of Three Musculoskeletal Physical Examination Techniques Used to Assess Motion in Three Planes While Standing三种用于评估站立时三平面运动的肌肉骨骼物理检查技术的评定者间信度
PM&R
IF0

