Epitaxial Growth of Zn and Zn-Ni Electrodeposits on Steel Sheets

The crystallographic aspects of zinc and zinc-nickel alloy electrodeposits on steel sheets have been studied by means of transmission electron microscopy (TEM) and O-lattice theory. TEM observation shows that the pure zinc and zinc-nickel hcp η-phase electrodeposits grow epitaxially on α-iron substrate with Burgers' orientation relationship. O-lattice theory predicts this relationship for η-phase while the increase of Ni content changes the dimensions of a-axis and c-axis. TEM observation shows the cube-cube parallel relationship between the zinc-nickel γ-phase and the substrate. This relationship can be also interpreted in terms of O-lattice theory.