2006 Volume 92 Issue 1 Pages 16-20
Zn-Nb films were formed on the steel sheet by helicon plasma sputtering under argon gas atmosphere of 1.0Pa, with RF power of 50W and DC power of 50mA to study the structure and the polarization property of the films using EPMA, X-ray diffraction and polarization curve measurement. Zn plate like crystals in Zn-Nb films were decreased with increasing Nb content, resulting in smooth surface all over the films at Nb content of 30mass% and above. The preferred orientation plane of Zn plate like crystals was (0002) at 0mass% Nb, while the orientation indices of (1011) and (1010) Zn were increased with increasing Nb content. At 30-60mass% Nb, the X-ray diffraction spectra showed halo pattern characteristic of anomalous structure. The corrosion current of Zn-Nb films, which was determined by polarization curves in 3% NaCl solution, decreased with increasing Nb content to reach the minimum value at 30-60mass% Nb of anomalous structure.
