A solution flow type microdroplet cell was applied to form a local copper line on a non-conductive substrate such as epoxy resin. During copper deposition, a copper rod was mounted in the epoxy resin as an electric feeding point. Such a copper line, which can be formed on the epoxy resin on flat and curved surfaces, can be removed from the epoxy resin, suggesting that this technique is applicable to form metal microstructures. The influence of the stage moving speed and applied current on the copper line thickness, shape, and conductivity were also investigated.

抄録全体を表示

Sulfur-added vanadium pentoxide (S-V₂O₅) powder prepared using our method was applied to the cathode active material used in magnesium rechargeable batteries. The preparation of S-V₂O₅ from a sulfur and vanadium pentoxide mixture was done with low-temperature plasma generated using carbon felt and 2.45-GHz microwave (CF-MWP). The S-V₂O₅ structure was investigated using XRD, XPS, Raman spectroscopy, and DRS-FTIR. Results revealed that the S-V₂O₅ particle surface contains sulfur atoms and that its structure is amorphous, like xerogel, although the bulk preserved the same structure as that of V₂O₅ crystal. Charge-discharge tests for S-V₂O₅ showed exceedingly high specific capacity of 300 mAhg⁻¹, which far surpasses that of V₂O₅ (160 mAhg⁻¹). The cycle performance of S-V₂O₅ (300 mAhg⁻¹ after 20 cycles) was also more stable than that of V₂O₅ (70 mAhg⁻¹ after first cycle). Moreover, the discharge voltage and the specific capacity did not degrade under any discharge rate condition from C/2 to C/10.

抄録全体を表示

In relation to the evaluation of corrosion resistance of zinc-coated steel sheets with chemical conversion coatings, evaluation of white rust occurrence is commonly conducted by visual observation of the specimens. However, because large individual variation exists in evaluation by visual observation and minute white rust is generated on the specimen surface, it is difficult to evaluate corrosion resistance objectively. An evaluation method was developed to appropriately evaluate the corrosion resistance of zinc-coated steel sheets with chemical conversion of coatings. It can visualize minute white rust accurately using low-angle lighting, a line scan camera, and a linear stage. Furthermore, the corrosion area ratio of the white rust can be evaluated quantitatively using image analysis. Good correlation was found between the developed quantitative analysis method and evaluation by visual observation.
The developed quantitative analysis method is applicable to various corrosion tests such as the exposure test, the salt spray test (SST), the combined cyclic corrosion test (CCT), and a new accelerated corrosion test (ACTE: Accelerated Corrosion Test for Electrical appliances). Superior correlation was found between the ACTE results and corrosion in actual environments. The ACTE test can estimate the influence of the amount of deposited sea salt on corrosion resistance of materials. The ACTE test and the developed quantitative analysis method enable appropriate evaluation of the corrosion resistance of zinc-coated steel sheets with chromate-free coatings.

抄録全体を表示