シアン化銅メッキの結晶構造に及ぼすメッキ条件, 添加剤の影響について

Abstract

In the previous papers, the author discussed the effects of plating conditions and additives on bright and leveling action and cathode polarization in copper cyanide bath. It was found that these conditions had very significant effects in deposits. Judging from the above fact, the plating conditions and additives may have some effects on crystalline structure of copper deposits.In this paper, there are reported the results of observation of crystalline structures by means of X-ray diffraction and observation of surface appearance by electron microscope.The results were summarized as follows.1) The crystal form of copper obtained from cyanide plating bath was quite the same as that of copper obtained by other processes, or it was face centred cubic lattice.2) The crystalline structures of the deposits from non-additive baths had no orientation, but the grain size of crystallites was relatively larger.3) Lead deposited from the baths, into which lead salts had been added. It formed crystal nuclei, from which copper crystallized radially in all directions. Accordingly, the surfaces were rough and the crystals had no orientation.4) The copper deposits from the baths containing sulfur compounds, having remarkable effects in brightness, such as thiocyanide, thiosulfate, etc. exhibited very strong orientation on [111] plane and the crystallites were very fine.5) The copper deposits from the baths containing organic compounds such as surface active agents exhibited weak orientation on [200] plane.