Micro- and Nanostructure of Zn Whiskers and Their Coating

To understand the mechanisms at the origin of whisker formation and growth, a Zn-electroplated steel prone to whiskering was studied. Several samples were prepared from different locations of the electroplated plate. Care was taken to extract samples at the root, in the nodule, or away from whiskers. Samples were characterized using electron backscattered diffraction (EBSD). Crystallographic data from EBSD show that recrystallized regions are present at the root of whiskers and in their nodules. These observations support whisker growth models based on recrystallization. In addition, atom probe tomography samples were prepared in the center of whiskers. The distribution of Zn atoms is almost homogeneous and no impurities are present in the whiskers.