镁合金表面前处理浸锌工艺及电镀铝研究

Pretreatment Process and Electroplating on Surface of Magnesium Alloy

重点研究了镁合金前处理过程中浸锌工艺参数对浸锌效果的影响及电镀时电流密度对铝镀层品质的影响。利用SEM及EDS分析了浸锌层及镀层的表面形貌、断面形貌,结合力学性能和成分分析,确定了镁合金前处理方案及后序电镀时的电流密度。结果表明,选取ZnSO4-K4P2O7体系浸锌液浸锌,在75℃时浸锌7min可以得到较好的浸锌层,电镀时采用为3.5～4.0A/dm2的电流密度得到的铝镀层结合性能好、均匀致密、纯度高。

Effects of processing parameters on zinc-immersion effects in pretreatment process and of current density on Al plating layer in electroplating process were analyzed for Magnesium alloy. The surface and fracture morphologies of zinc-immersion layer and electroplating layer on the surface of the alloy were observed by SEM (scanning electron microscope) and EDS (energy dispersive spectrum). Based on analyses of mechanical properties and composition,the pretreatment sketch of magnesium alloy and current density in subsequent electroplating process were designed. The results indicate that Al-plating layer with desirable bonding and high purity as well as uniformly compact structure on surface of Mg alloy can be obtained in ZnSO4-K4P2O7 solution for 7 min at 75℃,and with 3.5~4.1 A/dm2 during electroplating process.