A356合金化学镀Ni-P工艺及其性能研究

PREPERATION AND PERFORMANCE OF ELECTROLESS Ni-P PLATING ON A356 ALLOY

用直接化学镀Ni-P和先电镀Ni后化学镀Ni-P两种方法在A356合金表面施加镀层.利用恒电位仪、盐雾实验、扫描电镜和显微硬度计等分析测试手段研究了两种工艺处理后镀层的性能.结果表明:两种不同工艺得到的镀Ni-P样品均具有优异的耐蚀性和较高的硬度,对Al合金基体均有很好的保护作用;其中带镀Ni中间层的化学镀Ni-P层更致密,具有更好的耐蚀性和硬度.

In order to improve the corrosion resistance of A356 alloy, electroless Ni-P coatings were plated on the A356 alloy with and without a Ni pre-electroplating and then their corrsion performance was investigated by potentiodynamic polarization, salt spary test, SEM and microhardness. The results showed that the two kinds of coatings showed excellent corrosion resistance and high hardness, which protected the alloy effectively. In addition, the Ni-P coating with a Ni pre-electroplating had better corrosion resistance and higher hardness than the direct electroless Ni-P plating.