ギ酸添加浴を用いた高効率高速クロムめっき II. 光沢クロムめっき形成に及ぼす電極表面の3価クロムイオン濃度の影響 <研究論文>

High-Efficient and High-Speed Chromium Deposition in a Formic Acid Bath II. Influence of Chromium Ion Concentration in the Vicinity of the Cathode on the Appearance of Chromium Deposits

矢吹 彰広

安部 了介

松村 昌信

表面技術

A defect associated with the use of the Sargent bath, a widely-used device for chromium plating, is the substantially lower current efficiency of chromium, compared to that of other metals. It has been reported that the use of a formic acid bath leads to the production of amorphous-structured chromium deposits with a higher current efficiency. However, it is difficult to use this process commercially, because of difficulties involved in maintaining the bath. In this paper, the concentration of Cr3+ ion in the vicinity of the cathode in a formic acid bath was estimated from the current density, the aging time of the bath and the rotating speed of the rotating disk electrode (RDE) apparatus. The results show that Cr3+ concentration plays the most important role in determining the appearance of the deposited metal. The effect of formic acid and sulfuric acid on the chromium deposit was investigated, and the optimum Cr3+ concentration in the vicinity of the cathode on the chromium deposition process was determined. Taking these results into account, the conditions required for obtaining a bright deposit with a high current efficiency at a high deposition rate could be predicted, resulting in a bright deposit with a current efficiency of 64.8-0x1.fe3a0000008p+0t a deposition rate of 17.1μm/min.

High Current Efficiency

High Speed Deposition

Chromium Ion Concentration

Current Density

Rotating Disk Electrode

金属工学・鉱山工学 [ 560 ]

日本語

表面技術協会

本文データは学協会の許諾に基づきJ-STAGEから複製したものである

Copyright (c) 2005 (社)表面技術協会

[ISSN] 0915-1869

[DOI] 10.4139/sfj.55.139

[NCID] AN1005202X

[DOI] http://dx.doi.org/10.4139/sfj.55.139