Development of Electro-discharge Coating for Coloring Treatment with Titanium powder green compact electrode
Date Issued
2005
Date
2005
Author(s)
Lin, Kuan-Fu
DOI
zh-TW
Abstract
The function and purpose of surface engineering utilizing various kinds of surface modification techniques are to improve the particular properties of the workpiece. In this research, we propose a new surface coloring treatment, utilizing Electro-Discharge Coating (EDC) and oxidation, to make the oxide layers piled up on the SUS304 stainless steel substrate in the distilled water by using Ti powder green compact electrode. The following characteristics of the surface layers were investigated in this study: thickness, roughness, hardness, surface condition, and color tone. During this process, the effects of peak current, pulse duration, and duty factor were discussed respectively.
The results revealed that the higher peak current can make the thickness of oxide layers thicker due to the larger discharging energy, and it would make the surface roughness worse, owing to the larger unit volume of melting metal and the formation of the dendritic precipitates. As the pulse duration time was under 31μs, the thickness of oxide layers would grow with the increasing pulse duration time. The surface roughness would get worse with the elongation of pulse duration time. The value of duty factor turned from 0.33 to 0.5, the thickness of the layers would get thicker thereupon, but when the duty factor became to 0.8, the reducing number of effective discharge would make the layers thinner. When the thickness of the surface layers became thicker, an increasing of the surface layers hardness was observed. As a conclusion, peak current affected the amount and the dimension of the melting powder mainly, pulse duration time would influence the temperature of the gap, and the cooling time were decided by duty factor.
Subjects
放電披覆
氧化
發色
coloring
EDC
oxidation
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-94-R91522730-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):c48d5407d19b8251171b87f46069e299