Experimentation and Analysis into Micro-Hole Machining of Ti-6Al-4V by Micro-EDM Using Boron Carbide Powder Mixed De-Ionized Water

2014 ◽  
Vol 4 (1) ◽  
pp. 22-41 ◽  
Author(s):  
G. Kibria ◽  
I. Shivakoti ◽  
B. Bhattacharyya
Keyword(s):  
Boron Carbide ◽  
Electrode Surface ◽  
Machining Process ◽  
Carbide Powder ◽  
Chemical Compositions ◽  
Tool Electrode ◽  
Micro Edm ◽  
Machined Surface ◽  
Micro Hole ◽  
Hole Machining

In micro-electrical discharge machining (micro-EDM), dielectric plays a significant role during the machining process as different types of dielectrics encounters different chemical compositions, cooling rates and dielectric strengths. Therefore, while employing these different dielectrics, dissimilar process responses are accounted when machining in EDM at micron level. The present paper investigates micro-EDM characteristics such as material removal rate (MRR), tool wear rate (TWR), overcut (OC), taperness and machining time (MT) during micro-machining of through holes on Ti-6Al-4V superalloy employing de-ionized water based dielectric other than conventional hydro-carbon oil i.e. kerosene. The paper also includes the comparative study of the micro-EDM machining characteristics employing boron carbide (B4C) powder as additive in de-ionized water dielectric at different discharge energies. The results show that MRR and taper of micro-hole are better and TWR is less employing B4C additive in the dielectric than pure one, i.e. the productivity is improved and same micro-tool can be used for machining an array of micro-holes. Surface topography and recast layer formed during micro-hole machining by micro-EDM has also been investigated based on optical and SEM micrographs. Energy dispersive spectroscopy (EDS) analysis of machined surface as well as tool electrode surface has been done and the results show that there is significant amount of infusion of tungsten element onto the machined surface. A significant amount of carbon element is found onto the tool electrode surface.

CAD/CAM Integration System of 3D Micro EDM

2007 ◽  
Author(s):  
Hao Tong ◽  
Jing Cui ◽  
Yong Li ◽  
Yang Wang
Keyword(s):  
Real Time ◽  
Numerical Control ◽  
Machining Process ◽  
Tool Electrode ◽  
Electrode Wear ◽  
Micro Edm ◽  
Model Design ◽  
Integration System ◽  
Cad Cam ◽  
Micro Structures

In 3D scanning micro electro discharge machining (EDM), the CAD/CAM systems being used in mechanical milling of numerical control (NC) are unable to be applied directly due to the particularity of tool electrode wear. Based on industry computer and RT-Linux software platform, a CAD/CAM integration system of 3D micro EDM is developed. In the developed CAD/CAM integration system, the hardware includes mainly a micro feed mechanism for servo control, XY worktable, a high frequency pulse power supply, monitoring circuits etc., and the functions consist of model design, scanning path planning and simulation, NC code generation and post processing, real-time compensating of tool electrode wear, and machining control of states and process. The method of double buffer storage is adopted to transmit numbers of NC machining data. Servo scanning EDM method is used to realize real-time electrode wear compensating and thereby 3D micro structures are machined automatically. The machining experiments are made about model design, parameters optimizing, and process control. The typical 3D micro structures with space curved surfaces and lines have been machined such as micro prism, micro half tube, camber correlation line, and so on. The machining process and results show that the CAD/CAM integration system has the characters of higher real-time, reliability, and general using.

Generation of High Aspect Ratio Micro Holes by a Hybrid Micromachining Process

2007 ◽  
Author(s):  
Murali M. Sundaram ◽  
Sridevi Billa ◽  
Kamlakar P. Rajurkar
Keyword(s):  
Aspect Ratio ◽  
Ultrasonic Vibration ◽  
Machining Process ◽  
Hole Drilling ◽  
Micro Edm ◽  
Shape Distortion ◽  
Machining Time ◽  
Machined Surface ◽  
Electro Discharge Machining ◽  
Debris Removal

Drilling a micro hole with an aspect ratio above 10 is a challenging task for any-micromachining process. In micro electro discharge machining (micro EDM), a proven metallic micromachining process, this is due to the problems associated with debris removal. In such cases, where the capabilities of existing macro machining methods are constantly being challenged, innovative micro manufacturing approaches are required to make progress. Hybrid micromachining is one such approach in which the synergy of constituent processes is exploited to achieve desired results. In this paper, the results of ultrasonic vibration assisted micro electro discharge machining process are presented. This hybrid process is capable of deep hole drilling with aspect ratio of 20 in austenitic stainless steel by overcoming the limitations in the debris removal faced in the typical micro EDM process. Other benefits of ultrasonic vibration are the savings in machining time, and less tool wear. It is also noticed that the ultrasonic vibration causes some shape distortion and produces rougher machined surface.

Research on Chip Breaking Feature of the Micro Hole Vibration Drilling

2011 ◽  
Vol 694 ◽  
pp. 616-619
Author(s):  
Peng Zhang ◽  
Xing Yu Guo ◽  
Kang Pei Zhao ◽  
Li You Zhu
Keyword(s):  
Machining Process ◽  
Chip Breaking ◽  
Process Effects ◽  
Micro Drilling ◽  
Micro Hole ◽  
Breaking Mechanism ◽  
Vibration Drilling ◽  
On Chip ◽  
Hole Machining ◽  
Chip Removal

It is often one of the most important issues for chip breaking and chip removal problems in the hole machining process, especially for micro hole. The chip breaking mechanism of the vibration drilling is researched, and its chip breaking conditions is analyzed. The micro drilling experiments are carried to contrast the chip shape of common drilling and vibration one. It can be draw that the vibration drilling can realize the regular chip breaking, which is beneficial to chip removal in hole machining, the chip breaking feature is one of the fine process effects. This work further enriches the vibration drilling technology.

Performance of Micro-Hole Drilling by Ultrasonic-Assisted Electro-Chemical Discharge Machining

2012 ◽  
Vol 445 ◽  
pp. 865-870 ◽  
Author(s):  
Meifal Rusli ◽  
Katsushi Furutani
Keyword(s):  
Ultrasonic Vibration ◽  
Removal Rate ◽  
Glass Plate ◽  
High Amplitude ◽  
Machining Process ◽  
Hole Drilling ◽  
Tool Electrode ◽  
Conductive Materials ◽  
Electrolyte Level ◽  
Micro Hole

Electro-chemical discharge machining (ECDM) is one of nontraditional processes for micro-fabrication of non-conductive materials. A high applied voltage is preferable to form a gas film and to generate discharge in the film. However, accumulation of discharge heat often causes cracks of the surface because non-conductive materials have low heat conductivity. In this study, the effect of ultrasonic vibration and the electrolyte level on the performance of gravity-feed drilling by ECDM was investigated. Ultrasonic vibration was applied to a glass plate. A tungsten rod as a tool electrode was fed by gravity. Ultrasonic vibration changed the discharge behavior and improved electrolyte circulation. Although high amplitude ultrasonic vibration caused very dense and wide current pulses consistently during machining process, it decreased removal rate significantly. In addition, electrolyte levels affect single bubble size and the resistance in the electrolyte. Low electrolyte level will cause higher resistance, and higher temperature of the tool electrode and workpiece. A high bias current flew at a low electrolyte level without ultrasonic vibration. In this case, removal rate decreased and surface integrity was improved.

Microelectrode Array Fabrication by Micro-WEDM

2009 ◽  
Vol 69-70 ◽  
pp. 79-82 ◽  
Author(s):  
Yu Kui Wang ◽  
Zhen Long Wang ◽  
Mao Sheng Li ◽  
Wei Liang Zeng ◽  
M.H. Weng
Keyword(s):  
Microelectrode Array ◽  
Electrode Array ◽  
Machining Process ◽  
Hole Array ◽  
Micro Edm ◽  
Peak Current ◽  
Micro Hole ◽  
Discharge Duration ◽  
Micro Wedm ◽  
Array Fabrication

In the paper, in order to overcome machining limits in throughput and precision because of positioning error and tool wear of a single tool electrode, a method for the microelectrode array fabrication by micro-WEDM is described and assessed. Characteristics of the microelectrode array fabrication by micro-WEDM, such as machining open voltage, pulse peak current, discharge duration and servo feed rate so on, are investigated through a series of experiments. A 10 10 squared electrode array is machined by micro-WEDM and the width of each squared electrode is about 40µm. The microelectrode array with good quality is obtained by applying decreased open voltage and peak current, increased discharge duration and optimized machining speed. Then micro hole-array is processed by applying obtained electrode array in micro-EDM method. The diameter of each squared hole in the array is about 50 µm due to appropriate control strategy that per micro pulse energy is decreased and periodic jump-down is applied during the machining process. Experiments have demonstrated that the combination process of microelectrode array fabricated by micro-WEDM and micro-hole array done by micro-EDM is a novel method of process which makes it more feasible and efficient to fabricate microelectrode array and high-density hole-array.

Migration of Materials during Finishing Micro-EDM of Tungsten Carbide

2010 ◽  
Vol 443 ◽  
pp. 681-686 ◽  
Author(s):  
Muhammad Pervej Jahan ◽  
Mustafizur Rahman ◽  
Yoke San Wong
Keyword(s):  
Tungsten Carbide ◽  
Surface Defects ◽  
Surface Characteristics ◽  
Lower Amount ◽  
Tool Electrode ◽  
Micro Edm ◽  
Tungsten Electrode ◽  
Machined Surface ◽  
Workpiece Surface ◽  
Carbon Migration

Present study aims to investigate the migration of materials onto the surface of workpiece and electrode during fine-finish die-sinking and milling micro-EDM of tungsten carbide using pure tungsten electrode. The effect of materials transfer on the machined surface characteristics is also presented. The machined surfaces have been examined under scanning electron microscope (SEM) and energy dispersive X-ray (EDX) in order to investigate the changes in chemical composition due to the migration of materials. It has been observed that materials from both workpiece and electrode transfer to each other depending on machining conditions and discharge energy. A significant amount of carbon migrates to both electrode and workpiece surface due to the decomposition of dielectric hydrocarbon during breakdown. The migration occurs more frequently at lower gap voltages during finish die-sinking micro-EDM due to low spark gap and stationary tool electrode. Milling micro-EDM suffers from lower amount of carbon migration and fewer surface defects which improve the overall surface finish and reduce surface roughness significantly.

Fabrication of a micro-tool in micro-EDM combined with co-deposited Ni–SiC composites for micro-hole machining

2007 ◽  
Vol 17 (4) ◽  
pp. 763-774 ◽  
Author(s):  
Jung-Chou Hung ◽  
Wei-Chieh Wu ◽  
Biing-Hwa Yan ◽  
Fuang-Yuan Huang ◽  
Kun-Ling Wu
Keyword(s):  
Micro Edm ◽  
Micro Hole ◽  
Micro Tool ◽  
Sic Composites ◽  
Hole Machining

Micro-hole machining using micro-EDM combined with electropolishing

2006 ◽  
Vol 16 (8) ◽  
pp. 1480-1486 ◽  
Author(s):  
Jung-Chou Hung ◽  
Biing-Hwa Yan ◽  
Hung-Sung Liu ◽  
Han-Ming Chow
Keyword(s):  
Micro Edm ◽  
Micro Hole ◽  
Hole Machining

Study on Machining Characteristics of Ultrasonic Vibration Assisted Micro-EDM

2012 ◽  
Vol 217-219 ◽  
pp. 2163-2166 ◽  
Author(s):  
Tomohiko Ichikawa ◽  
Wataru Natsu
Keyword(s):  
Ultrasonic Vibration ◽  
Machining Process ◽  
Hole Drilling ◽  
Micro Edm ◽  
Discharge Energy ◽  
Machining Speed ◽  
Micro Hole ◽  
Short Circuits ◽  
Small Discharge ◽  
Machining Characteristics

The existence of debris in the inter-electrode area in micro-EDM interrupts the machining process. Applying ultrasonic vibration to the machining fluid helps circulate the machining fluid and remove the debris from the gap area, and thus reduce short-circuits and abnormal discharges. In this study, the effect of applying ultrasonic vibration to machining fluid in micro-EDM was experimentally investigated. It was found that a significant increase in the machining speed was realized by applying ultrasonic vibration. Also, with the vibration of the machining fluid, micro-hole drilling with ultra-small discharge energy became possible.

Generation of Microelectrodes for Micro EDM

2013 ◽  
Vol 581 ◽  
pp. 310-315
Author(s):  
Kohichi Miura ◽  
Shun Ichiro Kohmo ◽  
Takazo Yamada ◽  
Hwa Soo Lee
Keyword(s):  
High Precision ◽  
Thrust Force ◽  
High Accuracy ◽  
Micro Edm ◽  
Turning Operation ◽  
Micro Holes ◽  
Micro Hole ◽  
Short Time ◽  
Hole Machining ◽  
Edm Process

In order to fabricate micro holes by EDM process, microelectrodes with high accuracy of form are needed. At present, micro electrodes are generated by grinding and/or on-machine EDM operations and then it is well known that efficient productivity of micro electrodes cannot be realized. Controlling method of thrust force for micro shaft is already proposed. Applying this method, thrust force is controlled to be 0 in turning operation, therefore microelectrodes are generated efficiently. Actually, microelectrode which diameter is less than 0.1 mm can be easily machined in short time. high-precision micro hole machining requires microelectrodes with high cylindricity. In this study, turning method for microelectrodes with high cylindricity is discussed.

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