超硬铝合金作为阴极在锌电积过程中的电化学行为

Electrochemical behavior of the super high strength aluminum alloy as a cathode in zinc electrodeposition

  • 摘要: 选取商业纯铝和超硬铝作为锌电积阴极,在ZnSO4-H2SO4体系中通过电化学测试研究两种阴极的电化学行为,同时利用扫描电镜观察铝合金上电积锌初期形核,X射线衍射分析锌片结晶取向.研究结果表明:500 A·m-2电流密度下纯铝阴极的析出电位和交换电流密度分别为-1.541 V和7.74×10-11 A·cm-2,超硬铝阴极分别为-1.496 V和6.07×10-3 A·cm-2.合金元素的添加会增加初期形核位置,提高形核速率,而形核速率的提高在一定程度上抑制卤族元素对阴极的腐蚀.沉积3 h后,锌片结晶取向没有发生变化.超硬铝易发生烧板和鼓泡,电流效率低,只有84.54%;纯铝电流效率达到88.04%,且沉积锌平整、光滑,但阴极板容易被卤族元素腐蚀.

     

    Abstract: The characteristics of commercial pure aluminum and a super high strength aluminum alloy as cathodes in zinc electrodeposition were studied in this paper.In a ZnSO4-H2SO4 system,the electrochemical behavior of the two cathodes was investigated by electrochemical test,the initial nucleation was observed by scanning electron microscopy,and the crystalline orientations of zinc sheets were observed by X-ray energy dispersive spectrometry.The results show that under a current density of 500 A·m-2,the deposition potential and exchange current density of the commercial pure aluminum and super high strength aluminum alloy are -1.541 V,7.74×10-11 A·cm-2 and -1.496 V,6.07×10-3 A·cm-2,respectively.The addition of alloying elements can increase the initial nucleation sites and promote the rate of nucleation,but the increase of nucleation rate can inhibit cathode corrosion by halogen elements.There is no change in the crystalline orientations of zinc sheets after deposition for 3 h.The super high strength aluminum alloy is prone to burn the plate and blister,with a lower current efficiency of only 84.54%.The current efficiency of the pure aluminum is 88.04%,the morphology of deposited zinc is flat and smooth,but the cathode plate is easy to be corroded by halogen elements.

     

/

返回文章
返回