震動輔助傾斜式進給微放電加工微小孔之探討

Study of Micro-EDM Drilling with Assistance of Vibration and Inclined Feeding

梁豪文(Hao-Wen Liang)

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(2010年)

https://doi.org/10.6342/NTU.2010.02179

摘要

微放電加工是一種簡單、可加工任何可導電金屬材料之加工方式，常用在微小孔的加工，但在加工達一定深度時，加工液進入極間和放電渣排出都有一定難度，故微小孔之深度有所限制。本研究提出改變進給方向之傾斜式進給加工以及在電極上施加軸向的震動輔助兩種策略，改善加工液進入極間和放電渣排出之情形，使得微小孔深度可以增加，提高微放電加工微小孔之實用性。

本研究為解決加工液進入和放電渣排出之問題，在微放電加工機加上傾斜式進給及震動輔助機構。只使用傾斜進給加工時，採用斜向上進給可改善放電渣排出之問題，而斜向下進給可改善加工液進入之問題，兩者皆可得到較水平進給深之微小孔。其後在鋁合金6061上加工微小孔之實驗中，採用斜向上15度進給效果最佳，在深度方面可提供16.7%的改善；僅採用震動輔助加工時，震幅大小決定了極間擾動的程度，可改善放電渣排出之問題，是影響微小孔深度的主因，震動輔助對深度可提供33.3%的改善。歸納以上結果，若將兩者合併使用時，應使用斜向下進給及震動輔助策略，使得放電渣排出和加工液進入兩因素同時得到滿足，實驗結果發現，震動輔助搭配斜向下10度進給效果較佳，在深度方面可提供75%的改善。採用本研究提出之加工策略可在鋁合金6061上以直徑200μm之電極加出深寬比24的微小孔，在不鏽鋼上以直徑100μm之電極加工出深寬比26之微小孔以及以直徑50μm之電極加工深寬比18之微小孔。

關鍵字

微放電加工 ； 微小孔 ； 傾斜式進給 ； 震動輔助加工

並列摘要

Micro-EDM is a simple way of machining which is used in any conductive metal materials and wildly employed in micro-hole drilling. However, when drilling to a certain depth, some difficulties pertaining to dielectric fluid entering the discharge gap and the remove of debris will arouse, therefore the depth of micro hole is limited.

In order to solve the difficulties confronted when dielectric fluid entering the discharge gap and the remove of debris, this study proposed a method of micro hole drilling process based on micro electro-discharge machines added with inclined-feeding and vibration-assisted components. A deeper micro hole can be achieved in the inclined-feeding drilling process and the upward inclined-feeding would obtain a better debris removal rate while the downward inclined-feeding would obtain the good dielectric fluid entering. While machining micro hole on aluminum alloy 6061, a 15-degree-upward inclined feeding can offer a 16.7% improvement. In vibration-assisted machining, the magnitude of the amplitude is the main factor which influences the depth of micro hole and a 33.3% improvement in the depth can be obtained. When a 10-degree-downward inclined feeding and the vibration assisted are combined into practice, the remove of debris, the entering of dielectric fluid into the discharge gap and a 75% improvement in the depth can be achieved. With the developed machining strategies, drilling with an electrode of 200μm diameter on aluminum alloy 6061, a micro hole having an aspect ratio of 24 can be obtained, drilling with an electrode of 100μm diameter on stainless steel, a micro hole having an aspect ratio of 26 can be obtained and drilling with an electrode of 50μm diameter on stainless steel, a micro hole having an aspect ratio of 18 can be obtained.

並列關鍵字

Micro-EDM ； Micro hole ； inclined feeding ； vibration-assisted machining

參考文獻

[2] M. Kunieda and T. Masuzawa, “A Fundamental Study on a Horizontal EDM,” Annals of the CIRP, Vol. 37/1, 1988, pp.187-190

[3] T. Masuzawa, J. Tsukamoto and M. Fujino, “Drilling of Deep Microholes by EDM,” Annals of the CIRP, Vol.38/1, 1989, pp.195-198

[5] B.H. Yan, F.Y. Huang, H.M. Chow and J.Y. Tsai, “Micro-hole Machining of Carbide by Electric Discharge Machining,” Journal of Materials Processing Technology, Vol.87/1, 1999, pp139-145

[6] S.H. Yeo and L.K. Tan, “Effects of Ultrasonic Vibrations in Micro Electro-discharge Machining of Microholes,” Journal of Micromechanics and Microengineering, Vol.9/4 pp.345-352

[8] W.S. Zhao, Z.L. Wang,S.C. Di, G.X. Chi and H.Y. Wei, “Ultrasonic and Electric Discharge Machining to Deep and Small Hole on Titanium Alloy,” Journal of Materials Processing Technology, Vol.120/1-3, 2002, pp.101-106