Fabrication of Shapes with Overhang Using Micro-Boring Tools

2014 ◽  
Vol 1017 ◽  
pp. 485-488
Author(s):  
Kai Egashira ◽  
Kazuyuki Harada ◽  
Keishi Yamaguchi ◽  
Minoru Ota
Keyword(s):  
Tungsten Carbide ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Planetary Motion ◽  
Micro Turning ◽  
Tapered Hole ◽  
Cemented Tungsten Carbide

The boring of microholes has been carried out using micro-turning tools. There is a limitation, however, on machinable shapes using the tools employed therein, with the fabrication of shapes with an overhang being impossible. The fabrication of such shapes was therefore attempted in the present study using cemented tungsten carbide micro-boring tools processed by electrical discharge machining. Inner-grooving by turning was attempted in 0.15-mm-diameter holes, resulting in shapes with an overhang, such as a reverse-tapered hole. Furthermore, inner-grooving using tools moving in planetary motion was also attempted in 0.2-mm-diameter holes drilled in workpieces that were difficult to deal with by turning.

Fabrication of Micropins Using Micro Turning Tools

2012 ◽  
Vol 523-524 ◽  
pp. 76-80 ◽  
Author(s):  
Takuya Furukawa ◽  
Yosuke Nomura ◽  
Kazuyuki Harada ◽  
Kai Egashira
Keyword(s):  
Tungsten Carbide ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Cutting Tools ◽  
Depth Of Cut ◽  
Feed Speed ◽  
Tool Breakage ◽  
Micro Cutting ◽  
Hard Materials ◽  
Micro Turning

The turning of straight micropins with a diameter smaller than 10 µm, which has not been reported so far, was carried out using micro turning tools made of cemented tungsten carbide. Tools of 50 µm diameter were fabricated by electrical discharge machining, which is suitable for fabricating micro cutting tools because it can deal with hard materials and carry out micromachining. A turning machine designed especially for micro turning tools was used in the experiments. A brass workpiece was turned using a tool with a length of cut of 100 µm at a feed speed of 3.0 µm/s, feed per revolution of 0.06 µm and depth of cut of 10–11 µm. As a result, a straight micropin of 7.5 µm diameter and 80 µm length was successfully turned. Furthermore, turning was also performed using a tool with a length of cut of 50 µm at a feed speed of 3.0 µm/s, feed per revolution of 0.06 µm and depth of cut of 8.5–20 µm to fabricate a straight micropin of 3 µm diameter and 30 µm length. This micropin is the pin with the smallest ever diameter fabricated by turning, to the best of our knowledge, indicating the possibility of further minimization of the machinable size in turning. Turning properties were also investigated to determine the maximum depth of cut and feed speed that can be employed without tool breakage.

Mathematical modelling and comparative study of the machining characteristics in ultrasonic-assisted electrical discharge machining of cemented tungsten carbide (WC—10%Co)

2009 ◽  
Vol 223 (9) ◽  
pp. 1115-1126 ◽  
Author(s):  
M R Shabgard ◽  
M R Farahmand ◽  
A Ivanov
Keyword(s):  
Comparative Study ◽  
Tungsten Carbide ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Machining Parameters ◽  
Machining Performance ◽  
Ultrasonic Assisted ◽  
Pulse On Time ◽  
Ultrasonic Assisted Edm ◽  
Cemented Tungsten Carbide

The phenomena occurring between the electrodes in electrical discharge machining (EDM) are still not fully understood. Poor quantitative knowledge of the sources of variability affecting this process hinders the identification of its natural tolerance limits. This paper presents a systematic methodology for developing statistical models to show the relationship between important machining performance data (material removal rate (MRR), tool wear ratio (TWR), and surface roughness Ra) and the input machining parameters (pulse current and pulse-on time) in the EDM and ultrasonic-assisted EDM (US/EDM) of tungsten carbide. The models obtained were used to analyse the effects of input parameters on machining performance. A comparative study was conducted to determine the influence of ultrasonic vibration of the tool on machining performance. The results show that the MRR is significantly increased in ultrasonic-assisted EDM of cemented tungsten carbide (WC—10%Co), especially in finishing modes, and can be up to four times greater than that of conventional EDM. The TWR and Ra values are also increased slightly in US/EDM. The mathematical models presented can be used for optimization of the machining parameters.

Drilling of Rod End Faces Using Micro-Cutting Tools

2016 ◽  
Vol 874 ◽  
pp. 227-231
Author(s):  
Kai Egashira ◽  
Kenichi Kuriyama ◽  
Keishi Yamaguchi ◽  
Minoru Ota
Keyword(s):  
Tungsten Carbide ◽  
Body Length ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Cutting Tools ◽  
Feed Speed ◽  
Milling Machine ◽  
Micro Cutting ◽  
Turn Milling ◽  
Cemented Tungsten Carbide

There have been few reports on the drilling of microholes on rod end faces by cutting, which can be employed for fabricating micronozzles or microneedles. Such drilling was therefore attempted in the present study using a micro turn-milling machine with the tool and workpiece axes being parallel. The drilling was performed on the end faces of brass rods with cemented tungsten carbide micro-cutting tools processed by electrical discharge machining (EDM). As a result, a microhole 12‍ μm in diameter was successfully drilled using a 10-μm-diameter tool at a feed speed of 0.5‍ μm/s. The feed speed could be increased to 25 μm/s for a tool with a diameter of 20 μm and body length of 50 μm.

Surface Modification Process by Electrical Discharge Machining with Tungsten Carbide Powder Mixing in Kerosene Fluid

2019 ◽  
Vol 889 ◽  
pp. 115-122
Author(s):  
Van Tao Le ◽  
Tien Long Banh ◽  
Xuan Thai Tran ◽  
Nguyen Thi Hong Minh
Keyword(s):  
Surface Roughness ◽  
Tungsten Carbide ◽  
Electrical Discharge ◽  
Alloy Powder ◽  
Electrical Discharge Machining ◽  
Carbide Powder ◽  
Micro Hardness ◽  
Hard Materials ◽  
Tungsten Carbide Powder ◽  
Better Than

Electrical discharge machining (EDM) process is widely used to process hard materials in the industry. The process of electrical discharge is changed and called PMEDM when alloy powder is added in the oil dielectric. In the current study, the effect of tungsten carbide alloy powder added in the dielectric on the surface roughness (Ra) and the micro hardness of surface (HV) status of the workpiece SKD61 after machining is investigated. Studies show that the surface roughness and the micro hardness of surface obtained by PMEDM is generally better than that by normal EDM. The method can be applied for improving surface quality such as improving strengthening of molds and machine parts.

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