【作者】 吕玮；

【导师】 张永祥；

【作者基本信息】 福建师范大学 ， 物理化学， 2002， 硕士

【摘要】 为解决六价铬镀铬严重的环境污染问题，同时也为达到节约铬资源和节省能源的目的，从三价铬镀液中电沉积非晶态铁铬合金镀层在目前成为一条切实可行的技术路线。论文从三价铬镀液中电沉积非晶态铁铬合金镀层，研究了甘氨酸浓度、电流密度、pH值和温度等工艺参数对镀层中铬含量的影响，以及添加剂和杂质离子对电沉积过程的影响。用扫描电子显微镜（SEM）方法观察了不同沉积时间及添加剂加入后铁铬合金镀层的表面形貌。用X光电子能谱（XPS）分析了电沉积初始阶段的蓝膜组成和铁铬合金镀层中铁和铬的存在形式。用X射线衍射（XRD）方法分析了不同合金组成下的镀层结构。通过镀层的阳极极化曲线的测定，比较了晶态与非晶态结构镀层的耐蚀性能。用线性极化曲线及反应活化能的计算等探讨了三价铬电沉积铁铬合金的镀液中甘氨酸与各金属离子间的作用。 实验表明：在较优工艺条件下得到的铁铬合金镀层的铬含量可大于30％（wt％），外观光亮、结合力好，具有非晶态结构，显示出比晶态铁铬合金镀层更好的耐蚀性：Cr⁶⁺和Fe³⁺等杂质离子的存在影响镀层质量，可加抗坏血酸除去；一定量的添加剂NaF可增大阴极极化，扩大低电流密度区电沉积范围，增加镀层表面光亮性；在镀液中甘氨酸主要与Fe（Ⅱ）离子络合，使其反应活化能升高，阴极极化增大，析出电位负移，从而与铬一同析出，形成铁铬合金镀层。更多还原

【Abstract】 For resolve the serious pollution of the environment of hexavalent chromium plating, and for economize the chromium resources and energy, electrodeposition amorphous chromium-iron alloy from trivalent chromium electrolyte now has been extensive investigated. Electrodepositied amorphous chromium-iron alloy from trivalent chromium electrolyte, the paper studied the influence of changes in the concentration of glycine, current density, temperature and pH on Cr% of deposits. It is also studied that the effect of additive and impurity ion on electrodeposition. Surface morphology of amorphous chromium-iron alloy deposit from electrolyte cotaining addtives and for different times were investigated by scan electron microscope (SEM). The composition of blue film of electrodeposited prosess and the state of deposit’s metal element were studied by X-ray photoelectron spectroscopy (XPS).Crystal structure of deposits with different metal percent was analyzed by X-ray diffraction (XRD). Corrosion resistance of deposits was compared between crystalloid and amorphous state by anodic polarization curves. The action of the glycine and each metal ion in trivalent chromium electrolyte electroplating chromium-iron alloy were briefly discussed by linear sweep voltammetry (LSV) and calculation of action energies.Experiments show: electrodeposited in selected operation conditions, chromium-iron alloy deposit had a bright appearance and exhibited good adhesion on copper, whose Cr% was beyond 30wt%. The deposit has amorphous state and better corrosion resistance than crystalloid deposit. The impurity ion such as Cr6+, Fe3+ affect the quality of deposit, which can be get rid of by ascorbic acid. The selected additive NaF can enlarge the cathodic polarization, amplification the electrodeposition scope of low electric current density and increase the deposit’s shining. In the electrolyte the glycine reacted mainly with Fe(II) ion, which go up the Fe(II) action energy to increase cathodic polarization. Thus the deposited potential of Fe( II) become more negative ,and electrodeposite with chromium.更多还原