Z. Zhang
,
W.H. Leng
,
J.Q. Zhang
金属学报(英文版)
The influence of pH value of the electrolyte solution on the zinc electroplating process was studied by means of cyclic voltammetry and chronoamperometry approaches. The results shown that, under this experimental conditions and at high overpotentials, the nucleation of zinc is instantaneous, and the nuclear densities N increase with the overpotentials. While at low potentials, no distinguished nucleation current can be observed. High pH promotes the deposition either by drifting the initial depositing potential positively, or by increasing the depositing current through the change of the total charge of the adsorption process Qads, i.e., theｖstructure of electrochemical double layer.
关键词:
zinc electroplating
,
null
,
null
Z.Zhang
金属学报(英文版)
The influence of H3BO3 on the zinc electroplating was studied using electrochemical noise technique, cyclic voltammetry and steady-state polarization method. The results showed that,under the experimental conditions, the deposition of zinc followed the mechanism of two-dimensional nucleation and subsequent grain growth. The addition of H3BO3 into the electroplating solution prominently changes the nucleation and growth kinetics of zinc deposits, which is directly related to the features of electrocrystallization noise and the corresponding structure of the electrodeposits. The results also shown that the electrochemical noise (EN) technique can give more information about the electrodeposits structure and electroplating mechanism than other normal electrochemical measurements can give, such as steady-state polarization method and cyclic voltammetry technique.
关键词:
zinc electroplating
,
null
,
null
Z.Zhang
金属学报(英文版)
The influence of the concentration of Zn^2+ ions on zinc electroplating process was investigated by means of electrochemical noise (EN) and cyclic voltammetry methods in conjunction with the scanning electron microscopy (SEM) technique. It was found that the EN generated during the electroplating of dentritic or large polymeric zinc deposit has large potential oscillation amplitude and positive potential drift while the compact zinc deposit possesses small noise amplitude and little potential drift. With the change of rate determining step from diffusion-control through mixed-contro! to activation-control, the maximum relative energy obtained from wavelet analysis defined from the region with larger scales to those with smaller scales, and the EDP (relative energy distribution plot) can be us, as “fingerprints” of EN to characterize the electroplating process and the deposit structure. The results also showed that electrochemical noise technique can give more information about the electrodeposit structure than other normal electrochemical measurements, such as linear potential sweep method and cyclic voltammetry, technique.
关键词:
zinc electroplating
,
null
,
null
江茜
,
胡哲
,
黎冬瑛
,
戴建和
,
杨娟
,
王杰
,
陈楠
电镀与涂饰
以水性丙烯酸树脂为主成膜剂,水与乙醇为溶剂,辅以不同类型助剂,开发了一种高耐蚀无铬封闭工艺.研究了不同类型硅烷偶联剂、水性丙烯酸树脂及其用量对镀锌层封闭膜外观与耐盐雾时间的影响.结果表明,以酰氧基硅烷为硅烷偶联剂、用量为0.2％,以水性丙烯酸树脂JC-2051为主成膜剂、用量为50％,配合26％水、15％无水乙醇、1.5％水性防锈剂DH-810、0.9％有机胺酯(TPP)、0.9％固化剂Rad2100、1.7％防流挂剂Glide100和3.8％乙二醇丁醚制备的无铬封闭剂,对镀锌层进行封闭后所得到的封闭膜结合力为0级,中性盐雾试验96h内镀锌层不变色.
关键词:
镀锌
,
无铬封闭
,
水性丙烯酸树脂
,
耐蚀性
吴育忠
,
黄美玲
,
李伟善
,
马冲
,
左正勋
电镀与涂饰
采用中性盐雾试验和电化学阻抗谱,研究了酸性氯化钾镀锌、碱性无氰镀锌和碱性氰化物镀锌3种工艺所得镀锌层经三价铬彩色钝化后钝化膜的耐蚀性.结果表明:钝化后,酸性氯化钾镀锌层的耐蚀性最好,碱性无氰镀锌层次之,碱性氰化物镀锌层最差.在质量分数为1%的氯化钠溶液中,镀锌层钝化膜电阻的大小顺序为:酸性氯化钾镀锌>碱性无氰镀锌>碱性氰化物镀锌.酸性氯化钾镀锌钝化膜的耐蚀性较好可以与所得镀层中有机杂质夹杂较少有关.
关键词:
镀锌
,
三价铬
,
彩色钝化
,
耐蚀性
,
中性盐雾试验
,
电化学阻抗谱
张小勇
电镀与涂饰
介绍了溶锌工艺的原理及在无氰碱性镀锌中的应用,设计制作了溶锌设备,并对镀槽中的碳素钢阳极加以改进,确保了镀液中锌离子浓度的稳定,保证了电镀质量.
关键词:
电镀锌
,
溶解
,
设备
,
阳极
蒋建忠
,
缪树婷
,
郝利峰
,
韩生
电镀与涂饰
采用自制三价铬钝化液对镀锌的马口铁片进行钝化及硅烷封闭处理.钝化液组成为:Cr2(SO4)3 270 g/L,C6H8O7·H2O10 g/L,CoSO4·7H2O 100 g/L,NH4HF2 77 g/L,NaH2PO2·H2O48.8 g/L,NaNO3 32 g/L,D-葡萄糖酸钠15 g/L.讨论了钝化时间、温度、pH等工艺条件对钝化膜耐蚀性的影响,并研究了乙烯基三甲基硅烷封闭处理对钝化膜表面形貌和耐蚀性的影响.结果表明,在pH=1.8下对镀锌层室温钝化60 s所得钝化膜的耐蚀性最好,其在3.5％ NaCl溶液中浸泡240 h仍未出现白锈.采用乙烯基三甲基硅烷封闭处理后,钝化膜表面生成均匀的胶态膜,在中性盐雾试验中出现白锈的时间由未封闭时的95 h延长至115h,远远高于72 h的行业要求.
关键词:
电镀锌
,
三价铬钝化
,
硅烷封闭
,
耐蚀性
