電化學放電鑽孔加工品質提升之研究

The research of improvement of ECDM drilling quality

吳倫靜(Lun-Ching Wu)

指導教授 ： 廖運炫

國立臺灣大學/工學院/機械工程學研究所/碩士(2005年)

https://doi.org/10.6342/NTU.2005.02822

摘要

本文主要是針對電化學放電製程中鑽孔提升孔加工品質之研究。首先加入界面活性劑SDS於電解液中，觀察實際加工石英造成的影響。實驗結果顯示和未加入的情況相比，加入SDS於電解液中會造成電流密度的增加和更大量的氣泡的產生，因此造成更明亮的火花、更大的反應面積，同時擁有更穩定的電流波形；加入SDS後可以在較快的啄鑽速度下加工，會有較小的錐度、較好的加工表面品質，卻會出現過切的狀況，造成較大的擴孔率。使用適當的參數進行田口氏L18實驗，發現使用加入SDS的電解液，搭配低電壓、低頻率、低duty factor等電源參數的情況下可得到較小的錐度；如果需要降低擴孔率，應在未加入SDS於電解液的情況下，搭配低電壓和低duty factor，相較之下此時脈衝頻率則為較不重要的電源參數；如欲同時兼顧擴孔率和錐度，在加入SDS的情況下採用低電壓、低頻率、低duty factor，並搭配使用較小的電極進行加工。文中經由觀察和實驗的結果，推論出新的氣泡形成機制。

關鍵字

電化學放電加工 ； 界面活性劑 ； SDS ； 加工品質

並列摘要

This paper is aimed at the drilling quality improvement in electrochemical discharge machining (ECDM) process. The Sodium Dodecyl Sulfate (SDS) surfactant is added to the electrolyte and its effects on machining quartz are investigated. Experimental results show that the current density is increased, and there is more bubble release around the electrode as compared with that when machining in the electrolyte without SDS. As a result, the sparks become brighter and take place in a larger area. But on the other hand, a more stable pulse current is obtained. Hence, a less taper and a better quality but a little over size hole can be drilled with a higher engraving speed. The Taguchi L18 orthogonal array of experiment is adopted, and the appropriate machining parameters for various machining objectives are investigated. It is found that drilling with the use of SDS added electrolyte incorporated with the power source parameters of low voltage, pulse frequency and duty factor leads to a less taper hole. In order to reduce the over size error of a drilled hole, the use of electrolyte without SDS, low voltage and duty factor are recommended; while pulse frequency plays a minor role. When both of the over size and taper of a hole are concerned, machining should be conducted in the SDS added electrolyte using a smaller size electrode. A better quality hole can be drilled in less time. Furthermore, based on the observation of sparking process together with the experimental results, a new bubble forming mechanism during ECDM in the SDS added electrolyte is inferred.

並列關鍵字

ECDM ； surfactant ； SDS ； quality

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