%0 Journal Article
%T 硫酸盐体系三价铬沉积机理及镀层表征<br>Deposition Mechanism and Coating Characterization for the Trivalent Chromium Electrodeposition in Sulphate Electrolyte
%A 闫慧
%A 黄帅帅
%A 杨防祖
%A 田中群
%A 周绍民&lt
%A br&gt
%A YAN Hui
%A HUANG Shuai-shuai
%A YANG Fang-zu
%A TIAN Zhong-qun
%A ZHOU Shao-min
%J 电化学
%D 2018
%R 10.13208/j.electrochem.170441
%X 摘要 在新研发的硫酸盐三价铬镀厚铬的镀液体系中, 运用线性扫描伏安法(LSV)和循环伏安法(CV)对三价铬在铜电极表面的电沉积过程进行研究, 并运用X射线荧光测厚仪、扫描电子显微镜(SEM)、X射线能量色散谱(EDS)、X射线衍射仪(XRD)、显微硬度计和Tafel曲线表征铬镀层厚度、形貌、组成、结构、显微硬度及在3.5wt% NaCl溶液中的耐蚀性. 结果表明, 在该体系中三价铬的沉积过程分两步进行(Cr3+ + e → Cr2+ , Cr2+ + 2e → Cr), 第一步得到1个电子, 受电化学过程和扩散过程共同控制, 第二步得到2个电子, 为扩散控制下的不可逆过程; 该镀层为瘤状纳米晶结构, 镀层中含有少量的铁元素(1.10 wt%), 显微硬度达到789.2 Hv, 镀层在3.5wt% NaCl溶液中的腐蚀电位(Ecorr)为-0.29 V, 腐蚀电流密度(jcorr)为9.26×10-5 A·dm-2.<br>Linear sweep voltammetry (LSV) and cyclic voltammetry (CV) were used to study the electrodeposition mechanism of trivalent chromium on a copper electrode in the novel sulphate electrolyte for thick trivalent chromium plating. The thickness, morphology, composition, microhardness, and structure, as well as the corrosion resistance in 3.5wt% NaCl solution of the trivalent chromium coatings were investigated by X-ray fluorescence gage, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), microhardness tester, X-ray diffraction (XRD) and Tafel curve measurements. The results showed that the electrodeposition of trivalent chromium involved two consecutive one electron reduction steps. The first step, Cr3+ + e → Cr2+,is controlled by the electrochemical reduction and diffusion processes, and the second step, Cr2+ + 2e → Cr, is an irreversible process under the diffusion control. The trivalent chromium coating exhibited nodular nanocrystalline structure and contained a small amount of iron (1.10wt%). The microhardness of the coating reached to 789.2 Hv. The corrosion potential (Ecorr) and corrosion current density (jcorr) of the coating in 3.5wt% NaCl solution were determined to be -0.29 V and 9.26×10-5 A·dm-2, respectively
%K 三价铬
%K 硫酸盐
%K 厚铬
%K 电沉积
%K 机理
%K 镀层表征.
%K &lt
%K br&gt
%K Trivalent chromium
%K Sulphate
%K Hard chromium
%K Electrodeposition
%K Mechanism
%K Coating Characterization.
%U http://electrochem.xmu.edu.cn/CN/abstract/abstract10388.shtml