scholarly journals Desktop Micro-EDM System for High-Aspect Ratio Micro-Hole Drilling in Tungsten Cemented Carbide by Cut-Side Micro-Tool

Micromachines ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 675 ◽  
Author(s):  
Yung-Yi Wu ◽  
Tzu-Wei Huang ◽  
Dong-Yea Sheu
Keyword(s):  
Aspect Ratio ◽  
Large Scale ◽  
Cemented Carbide ◽  
Hole Drilling ◽  
Scale Production ◽  
Micro Edm ◽  
Micro Holes ◽  
Micro Hole ◽  
Micro Tool ◽  
Micro Tools

Tungsten cemented carbide (WC-Co) is a widely applied material in micro-hole drilling, such as in suction nozzles, injection nozzles, and wire drawing dies, owing to its high wear resistance and hardness. Since the development of wire-electro-discharge grinding (WEDG) technology, the micro-electrical discharge machining (micro-EDM) has been excellent in the process of fabricating micro-holes in WC-Co material. Even though high-quality micro-holes can be drilled by micro-EDM, it is still limited in large-scale production, due to the electrode tool wear caused during the process. In addition, the high cost of precision micro-EDM is also a limitation for WC-Co micro-hole drilling. This study aimed to develop a low-cost desktop micro-EDM system for fabricating micro-holes in tungsten cemented carbide materials. Taking advantage of commercial micro tools in a desktop micro-EDM system, it is possible to reach half the amount of large-scale production of micro-holes. Meanwhile, it is difficult to drill the deep and high aspect ratio micro-holes using conventional micro-EDM, therefore, a cut-side micro-tool shaped for micro-EDM system drilling was exploited in this study. The results show that micro-holes with a diameter of 0.07 mm and thickness of 1.0 mm could be drilled completely by cut-side micro-tools. The roundness of the holes were approximately 0.001 mm and the aspect ratio was close to 15.

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.

High aspect ratio micro-hole drilling aided with ultrasonic vibration and planetary movement of electrode by micro-EDM

CIRP Annals ◽  
2009 ◽  
Vol 58 (1) ◽  
pp. 213-216 ◽  
Author(s):  
Z.Y. Yu ◽  
Y. Zhang ◽  
J. Li ◽  
J. Luan ◽  
F. Zhao ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Ultrasonic Vibration ◽  
High Aspect Ratio ◽  
Hole Drilling ◽  
Micro Edm ◽  
Micro Hole

Influence of the Planetary Movement of Tool on the Aspect Ratio of Micro Holes Machined by Micro-Ultrasonic Machining

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Senwang Lei ◽  
Zuyuan Yu ◽  
Kai Zhou ◽  
Jianzhong Li ◽  
Renke Kang
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Ultrasonic Machining ◽  
Processing Efficiency ◽  
Machining Speed ◽  
Micro Holes ◽  
Hard And Brittle Materials ◽  
Micro Hole ◽  
Micro Tool ◽  
Movement Parameters

The micro-ultrasonic machining (USM) is suitable for machining hard and brittle materials. When a micro hole is drilled deeply using micro-USM, machining speed slows down and the breakage of micro tool may occur. To solve this problem, this paper proposes the application the planetary movement of micro tool in high-aspect ratio micro holes drilling by micro-USM. The micro holes of about 92 μm in diameter with an aspect ratio larger than ten have been machined. The processing efficiency has been improved. The influence of planetary movement parameters on processing efficiency has been investigated

Experimental Study of Micro Tools Fabricated by Electrochemical Machining

2010 ◽  
Author(s):  
Ronnie Mathew ◽  
Sagil James ◽  
M. M. Sundaram
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Thermal Stresses ◽  
Electrochemical Machining ◽  
Experimental Conditions ◽  
Aspect Ratios ◽  
Micro Holes ◽  
Machining System ◽  
Micro Tool ◽  
Micro Tools

Accurate and precise micro tools are essential for the micromachining of highly complex features in a wide variety of engineering materials including metals and ceramics. Simple shapes like cylindrical rods with micrometer level dimensions are increasingly being used as micro tools in processes such as micro ultrasonic machining. High aspect ratio tools are necessary to produce deep micro holes and other high aspect ratio structures. Micro tools produced by the well known wire electro-discharge grinding suffer from deformation due to the thermal stresses. Therefore, alternate micro tool manufacturing techniques are being explored actively. In this paper, the manufacturing of micro tools by micro electrochemical machining (ECM) is discussed. The micro tools are made under different experimental conditions using an in-house built micro electrochemical machining system and analyzed for tool tip radii and cone angles. Further, the feasibility of extremely high aspect ratio micro tools is studied. Using micro ECM, micro tools having mean diameters of 10 microns with tips as small as 50 nm and aspect ratios of the order of 300 are achieved.

Generation of Microelectrodes for Micro EDM

2012 ◽  
Vol 523-524 ◽  
pp. 310-315
Author(s):  
Kohichi Miura ◽  
Shun Ichiro Kohmo ◽  
Ryuichi Naruoka ◽  
Takazo Yamada ◽  
Hwa Soo Lee
Keyword(s):  
Aspect Ratio ◽  
Thrust Force ◽  
Micro Edm ◽  
Electrode Geometry ◽  
Electric Discharge Machining ◽  
Machining Time ◽  
Electrode Consumption ◽  
Generating Method ◽  
Micro Holes ◽  
Micro Hole

A new turning method to control the thrust force to be zero has already been proposed in our laboratory, and it is shown that micro shafts which diameters are less than 1 mm can be generated stably and repeatedly by applying this turning method. As an application of this turning method, a generating method of electrodes of micro electric discharge machining, EDM, for micro holes is proposed. When drilling a micro hole by EDM using an electrode with high aspect ratio, machined chip is difficult to be exhausted. Therefore, machining time has a tendency to be long and the electrode consumption becomes large. Standing in such a viewpoint, a new method to exhaust the chip smoothly by forming the micro electrode geometry is proposed in this paper. As the results of this study, it is confirmed that the machining time of micro holes can be shorted and the consumption of electrode can also be decreased experimentally.

Development of a Reverse Micro EDM-Drilling for Holing Diamond-Tool

2010 ◽  
Vol 126-128 ◽  
pp. 802-807
Author(s):  
Shun Tong Chen ◽  
Zong Han Jiang ◽  
Yi Ying Wu ◽  
Hong Ye Yang
Keyword(s):  
Diamond Tool ◽  
Dimensional Accuracy ◽  
Sintered Alloy ◽  
Micro Edm ◽  
Hollow Shaft ◽  
Discharge Capacitance ◽  
Micro Holes ◽  
Micro Hole ◽  
Micro Tool ◽  
Edm Drilling

This study presents the development of a drilling technique for an innovative tabletop drilling machine that combines micro-EDM with drilling to fabricate micro-holes in diamond-tool. The mechanisms designs of double V-shaped bearings and double spindles which provide a precision clamping and vertical alignment for diamond-tool and micro-tube are devised to enable to machine a co-centric micro-hole for micro-tool. A diamond-tool, made with copper-based sintered alloy, is drilled by using the developed technique of co-centric micro-hole EDM-drilling into a hollow shaft which can create equilibrium of drilling forces, prevent a drilling squeezing to be occurred and enable to offer a temporary storing space for drilling chips. Relative experiments including the determinations of drilling ratio and discharge capacitance are carried out via this established machine. Experimental results show that excellent geometric and dimensional accuracy of micro-holes on the diamond-tool can be achieved.

A Method of Machining Micro Hole and Micro Cavity in Ceramics

2011 ◽  
Vol 130-134 ◽  
pp. 923-926 ◽  
Author(s):  
Jian Zhong Li ◽  
Tao Wu ◽  
Long Zhang
Keyword(s):  
Tool Path ◽  
Electrical Discharge Machining ◽  
Hole Drilling ◽  
Final Size ◽  
Shrinkage Ratio ◽  
Micro Electrical Discharge Machining ◽  
Micro Holes ◽  
Micro Hole ◽  
Micro Tool ◽  
Micro Cavity

For machining micro hole and micro cavity in ceramics, a manufacturing methods based on green machining have been systematically researched. The micro tool was prepared on-machine by micro electrical discharge machining (EDM). The tool size for micro hole drilling was determined based on extensive experimental results of the sintering shrinkage ratio and the gap caused by the removed ceramics particles between the tool and the workpiece to achieve the desired hole diameter. The tool path design was based on the tool size, the shrinkage ratio and the gap which is different from that in micro hole drilling. Micro holes with diameter of 100μm and micro cavities with upper surface size of 500μm×500μm was machined in ceramics successfully by this method. The final size error was controlled less than 2.25% in micro hole drilling and less than 2% in micro cavity generation.

Development and Application of a Micro-Honing-Tool

2009 ◽  
Vol 76-78 ◽  
pp. 189-194
Author(s):  
Shun Tong Chen ◽  
Ming Chie Yeh
Keyword(s):  
Surface Roughness ◽  
Hole Drilling ◽  
Micro Edm ◽  
Wire Edm ◽  
Uneven Surface ◽  
Novel Technique ◽  
New Process ◽  
Micro Hole ◽  
Micro Tool ◽  
On Line

The major aim of this study is to present a novel technique for honing the micro-hole. It is difficult that regarding the finish machining of the micro-hole that the diameter is less than 300 m. First, a new process that to on-line accurately fabricate the micro-honing-tool using micro-EDM, micro-co-deposition and micro-wire-EDM is proposed for honing the micro-hole. A micro rod for as the substrate of the micro-tool is formed by wire-EDM and then co-deposited with 0-2 m CBN-abrasives. Subsequently, it is axially and crisscross cut for an appropriate length by micro-wire-EDM to make the crotched microstructure. The whole processes are able to be on-line realized since all working positions are recorded in detail and fabrication technologies are offered sufficiently on the same system. As a result, per the same fabrication-system, the micro-honing process is also on-line conducted. The finished micro-honing-tool is employed directly without unloaded and reloaded. The grinding-block can compactly stick on the wall surface of the micro-hole due to the radial elasticity of the micro-tool and then fast grind away the uneven surface by removal of micro amount. Experimental results demonstrated that the circularity and surface roughness on the hole-wall is evidently improved. Comparing with the obtained machining surface by micro-EDM hole-drilling, the original surface roughness of near one-sixth time can be achieved. It is indicated that the micro-hole can be honed accurately using the proposed technique.

Experimental Investigation Into Sequential Micro Machining (SMM) for Micro Hole Drilling on SS–304

2019 ◽  
Vol 9 (4) ◽  
pp. 1-16
Author(s):  
Raju Mahadeorao Tayade ◽  
Biswanath Doloi ◽  
Biplab Ranjan Sarkar ◽  
Bijoy Bhattacharyya
Keyword(s):  
Xrd Analysis ◽  
304 Stainless Steel ◽  
Hole Drilling ◽  
Machining Parameters ◽  
Micro Machining ◽  
Machining Processes ◽  
Taper Angle ◽  
Micro Holes ◽  
Micro Hole ◽  
Ss 304

Sequential micro machining (SMM) is a strategy of machining applied for micro-part manufacturing. Due to the finding of new sequential machining combinations, the authors have presented a novel combination of micro-ECDM (µECDM) drilling and micro-ECM (µECM) finishing for producing micro-holes in SS-304 stainless steel. An experimental setup was developed indigenously to conduct both machining processes at one station. The sequential processes were employed with desirable machining parameters, during their individual execution. The most desirable parameter like machining voltage, for hole drilling by µECDM was decided by studying hole taper angle, radial overcut, etc. The µECDM generates a recast layer, to overcome the adverse effects of µECDM, with the µECM finishing applied subsequently. The experimental results of SMM indicate a reduction in hole taper angle, improved circularity, and better surface quality. The change of phase of material due to sequencing of µECDM and µECM processes was analyzed by an XRD analysis of SS-304.

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