镍镀层中微量六方晶格镍的存在与稳定性研究
Studies on the Existence and Stability of Hexagonal Structure Nickel in Electrodeposited Ni
Abstract
对由含糖精的WATTS液得到的镍镀层（含硫镍）和WATTS镍镀层（无硫镍）进行透射电镜观察及选区电子衍射实验，结果表明无硫镍镀层呈粒状结构，晶粒尺寸在100~500nM之间，属面心立方结构；含硫镍镀层为层状结构，层间距在700~1500nM之间，每层又由许多宽约200~300nM的小层组成，晶粒尺寸约20~30nM，大部分属面心立方结构，在层与层交界处发现有少量六方结构镍晶体，差示扫描量热法实验表明，在约180℃左右六方结构镍转化为更稳定的面心立方结构。 SulFur-containing Ni and sulFur-Free Ni deposits have been studied by means of transmission electron microscopy and selected area electron diFFraction.The results showed that sulFur-Free Ni deposit is of grainy structure, the grain size is about l00-500 nm and the structure is FCC, and sulFur-containing Ni deposit is of laminated structure, the layer thickness is about 200-300 nm, the gain size is about 20-30 nm.Besides FCC Ni,a hexagonal structure Ni is also Found between the layers in the sulFur-containing Ni deposit.The diFFerential scanning calorimetry experiment of the Ni deposits showed that the hexagonal structure Ni would be transFered into more stable FCC Ni at near l80℃.