High Aspect Ratio and Complex Shaped Blind Micro Holes by Micro EDM

CIRP Annals ◽  
2002 ◽  
Vol 51 (1) ◽  
pp. 359-362 ◽  
Author(s):  
Z.Y. Yu ◽  
K.P. Rajurkar ◽  
H. Shen
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Micro Edm ◽  
Micro Holes

Analysis of accuracy of high-aspect-ratio holes generated using micro-electric discharge machining drilling

2008 ◽  
Vol 222 (11) ◽  
pp. 1453-1464 ◽  
Author(s):  
M S Puranik ◽  
S S Joshi
Keyword(s):  
Aspect Ratio ◽  
Electric Discharge ◽  
High Aspect Ratio ◽  
Processing Parameters ◽  
Industrial Applications ◽  
Tool Electrode ◽  
Micro Edm ◽  
Electric Discharge Machining ◽  
Debris Accumulation ◽  
Micro Holes

Micro-electric discharge machining (micro-EDM) has evolved as one of the prominent processes to generate high-aspect-ratio and accurate micro-structures in many industrial applications. This paper presents an extensive experimental analysis of the micro-EDM process to explore the relationship between accuracy as a function of depth of micro-holes drilled using micro-EDM drilling. It is shown that a depth of 5.0 mm can be achieved by a 200 μm diameter tool electrode while controlling the regular process parameters, but beyond this length, the process is governed by a number of derived phenomena such as secondary sparking, debris accumulation, etc. instead of the regular processing parameters. The optimum depth of the hole that could be achieved with a good accuracy i.e. a minimum oversize lies between 2.5 and 5.0 mm, the largest depth that could be achieved was 8.33 mm. The highest aspect ratio achieved in this experiment was 15.63.

Machining of High Aspect Ratio Micro-Holes on Titanium Alloy Using Silver Nano Powder Mixed Micro EDM Drilling

2019 ◽  
Author(s):  
Chong Liu ◽  
Asif Rashid ◽  
Muhammad P. Jahan ◽  
Jianfeng Ma
Keyword(s):  
Titanium Alloy ◽  
Aspect Ratio ◽  
Surface Finish ◽  
High Aspect Ratio ◽  
Electrical Discharge Machining ◽  
Turbine Blades ◽  
Weight Ratio ◽  
Recast Layer ◽  
Micro Edm ◽  
Micro Holes

Abstract Titanium alloy Ti-6Al-4V is used extensively in aerospace engines because of its high strength-to-weight ratio and corrosion resistance. Machining of cooling holes in turbine blades for aerospace engines is one of the major challenges faced in aerospace industries. Ti-6Al-4V is known as a difficult to be machined material by conventional machining processes, and machining of micro-through-holes with diameter less than 100 microns is even more challenging. Therefore, the objective of this study is to investigate the feasibility of machining high aspect ratio micro-through holes in Ti-6Al-4V using micro electrical discharge machining (micro-EDM) with the silver (Ag) nanopowder mixed dielectric. The machining time, overcut, recast layer, crater size, aspect ratio and surface finish of the micro-holes were evaluated. In order to minimize the positional inaccuracy and spindle runout, the microelectrodes were fabricated in-situ using block micro-EDM process. In this study, as received electrode of 300 microns diameter tungsten wire was reduced to about 50 microns diameter rod by micro block EDM using a tungsten carbide block. The effect of powder concentration, gap voltage, capacitance and electrode rotational speed was studied. It is found that high quality micro-holes of about 50 microns diameter can be achieved successfully and repeatedly using powder mixed micro-EDM (PM-μEDM). The micro-holes generated by PM-μEDM provides comparatively smoother surface finish and minimal recast layer around the rim of the micro-holes. In addition, PM-μEDM process improves machining stability, thus allowing to minimize the hole size and quality, thus enhancing the aspect ratio of micro-holes.

High aspect ratio meso-scale parts enabled by wire micro-EDM

2002 ◽  
Vol 8 (6) ◽  
pp. 395-401 ◽  
Author(s):  
G. L. Benavides ◽  
L. F. Bieg ◽  
M. P. Saavedra ◽  
E. A. Bryce
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Micro Edm ◽  
Meso Scale

EDM of high aspect ratio micro-holes on Ti-6Al-4V alloy by synchronizing energy interactions

2020 ◽  
Vol 35 (11) ◽  
pp. 1188-1203 ◽  
Author(s):  
Ramver Singh ◽  
Akshay Dvivedi ◽  
Pradeep Kumar
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Micro Holes

A study on the machining of high-aspect ratio micro-structures using micro-EDM

2003 ◽  
Vol 140 (1-3) ◽  
pp. 318-325 ◽  
Author(s):  
H.S. Lim ◽  
Y.S. Wong ◽  
M. Rahman ◽  
M.K. Edwin Lee
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Micro Edm ◽  
Micro Structures

Fabrication of High-Aspect Ratio Micro Holes on Hard Brittle Materials -Study on Electrorheological Fluid-Assisted Micro Ultrasonic Machining-

2008 ◽  
Vol 389-390 ◽  
pp. 264-270 ◽  
Author(s):  
T. Tateishi ◽  
Nobuhito Yoshihara ◽  
Ji Wang Yan ◽  
Tsunemoto Kuriyagawa
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Brittle Materials ◽  
Electrorheological Fluid ◽  
Machining Accuracy ◽  
Machining Efficiency ◽  
Ultrasonic Machining ◽  
Auxiliary Electrode ◽  
Abrasive Grains ◽  
Micro Holes

Ultrasonic machining (USM) is an effective method for machining of hard brittle materials. In this process, the slurry is supplied to the gap between the workpiece and the ultrasonic vibrating tool, and the materials are removed by the impacts of the abrasive grains that are pressurized by an ultrasonic vibrating tool. The purpose of this research is to achieve precise and efficient microfabrication on hard brittle materials by USM. However, in the case of microfabrication, chipping which is generally observed around the edges of machined micro holes and grooves, deteriorates the machining accuracy. In addition, there is another problem in that the machining efficiency decreases with the progress of the machining. Electrorheological fluid-assisted USM has been proposed as a countermeasure to these problems. In the present study, the problems and countermeasures associated with the machining of high-aspect ratio micro holes in hard brittle materials by electrorheological fluid-assisted USM are investigated. By positioning an auxiliary electrode under the workpiece, it becomes possible to keep the electric field high even when the machining depth becomes large. As a result, high-precision and high-aspect ratio micro holes can be machined on hard brittle materials.

Modeling Aspect Ratio of a Micro EDM Hole

2010 ◽  
Vol 126-128 ◽  
pp. 829-834
Author(s):  
G. Yin ◽  
Z. Yu ◽  
C. An ◽  
J. Li
Keyword(s):  
Aspect Ratio ◽  
Electrical Discharge Machining ◽  
Micro Edm ◽  
Metallic Materials ◽  
Micro Electrical Discharge Machining ◽  
Proposed Model ◽  
Micro Holes ◽  
Micro Hole ◽  
The Difference ◽  
Discharge Gap

Micro electrical discharge machining (EDM) has the ability to drill micro holes with high accuracy in metallic materials. The aspect ratio of a micro hole generated by micro EDM is usually higher than those by other processes such as etching, mechanical drilling, and laser. However, it was found that the drilling speed of micro EDM slows down and even stops when the aspect ratio reaches a certain value. To understand this phenomenon, a theoretical model is proposed based on the fluid mechanics and surface tension. Experiments under different machining conditions are carried to verify this model. Experimental results agree with the theoretical values, which indicate the validity of the proposed model. The difference between the theoretical values and the real values might be caused by the debris and the temperature in the discharge gap, which are ignored in the model.

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