The Microstructure and the Prerred Orientation of Pb-Sn-Alloy Electrodeposits in Pulse Plating

파형점류전해에 의한 Pb-Sn 합금의 현미경조직 및 우선배향

The surface morphology and the proferred orientation of the Pb-Sn alloy electrodeposite were investated by the change of electrolysis conditions in pulse current electroplating. The preferred orientation of Pb-phase in alloy deposits was changed in the sequence of (110)longrightarrow(100)or(100)+(111)longrightarrow(111) with increasing peak current density, while that of $\beta$-Sn phase changed from (321)+(301)to(301)+(111) mixed orientation. The surface morphology was closely related to the preferred orientation of alloy electrodeposits. The alloy deposits, which had (100)or(111) for pb-phase and (321)or(100)(301)for $\beta$-Sn sespectively, showed the surface structure of granular crystallites. The alloy deposits whih mixed orientations for both phases had microstructure of closely the closely stacked crysrallites, which was inclined to the surface.