中文摘要：

将LC4铝合金进行硫酸阳极化处理,然后采用小电流密度（0.1 mA/cm^2）进行镀铜处理。XRD和EDS分析表明,小电流镀铜的沉积产物为金属铜,沉积的位置位于氧化膜多孔层的底部。结果表明,小电流镀铜能够使自腐蚀电位正移从而改善阳极氧化膜的耐蚀性。根据交流阻抗谱提出小电流镀铜后阳极氧化膜的等效电路。沉积铜对阳极氧化膜的改性作用使材料具有铜的电化学特性,是耐蚀性提高的根本原因。小电流镀铜处理与传统的电解着色工艺有本质区别,是一种新颖的提高阳极化铝合金耐蚀性的后处理方法。

英文摘要：

Copper plating at a low current density （0.1 mA/cm^2） was carried out on the anodic film of LC4 aluminum alloy. XRD and EDS results show that the deposition product is the metal of copper, which is deposited at the bottom of the porous layer of the anodic film. The polarization curves show that copper plating at a low current density （0.1 mA/cm^2） can remarkably improve the corrosion resistance of the anodic film. The equivalent circuit of the anodic film after copper plating is presented according to the impedance spectroscopy. The primary cause of the improvement is that the material has the electrochemical characteristic of the copper by the modification of copper plating. Essential difference exists between the copper plating at the low current density （0.1 mA/cm^2） and the traditional electrolytic coloring technology.