Japanese

Research Themes

Micro EDM | Micro Cutting | Micro Grinding | Micro USM

Micro EDM (Electrical Discharge Machining)

Electrical Discharge Machining of Submicron Holes Using Ultrasmall-Diameter Electrodes
The EDM of submicron holes using ultrasmall diameter was carried out. It was possible to drill holes of approximately 0.5 Ám diameter using silicon electrodes. These holes have the smallest reported diameter for holes drilled by EDM.

Paper Paper (KIT only) (Precision Engineering, Vol.34, No.1, 2010, pp.139-144)

Tool electrode fabricated by electrochemical machining0.5-Ám-diameter microhole

Electrical Discharge Machining of Submicron-Diameter Micropins
The EDM of submicron-diameter zinc micropins was attempted using a relaxation-type pulse generator. A micropin of 0.3 Ám diameter was processed, which is the smallest-diameter micropin fabricated by EDM.

Paper Paper (KIT only) (Key Engineering Materials, Vols.447-448, 2010, pp.238-241)

Fabricated 0.3-Ám-diameter micropin

Chamfering and Deburring of Back Sides of Micro-Through Holes by EDM
Chamfering and deburring by EDM were attempted using tool electrodes with the middle part thinner than the other parts. Chamfering was successfully carried out on the back sides of a microhole with a diameter of 60 Ám, a deep hole with an aspect ratio of 5 and a noncircular hole.

Paper (Journal of the Japan Society of Electrical Machining Engineers, Vol.43, No.104, 2009, pp.172-178)

Tool electrode with the middle part thinner than the other partsMicrohole with the back side chamfered

EDM at Low Open-Circuit Voltage
The possibilities for EDM at open-circuit voltages lower than 30 V are examined using a relaxation-type pulse generator. Although the material removal rate is very low, machining is possible even at an open-circuit voltage of 2 V

Paper (International Journal of Electrical Machining, No.10, 2005, pp.21-25)

Fabricated 1-Ám-diameter micropinHole drilled at open-circuit voltage of 2 V.

Electrical Discharge Machining with Ultralow Discharge Energy
The possibility of EDM with ultralow discharge energy has been investigated using a relaxation-type pulse generator. The machining proceeded at open-circuit voltages lower than 15 V. The maximum discharge energy per pulse is as small as approximately 3 nJ under these conditions.

Paper Paper (KIT only) (Precision Engineering, Vol.30, No.4, 2006, pp.414-420)

EDMed surface (20 V)EDMed surface (12.5 V)

Planetary EDM of Micro Holes
The planetary EDM of microholes of less than 50 Ám in diameter has been attempted. The planetary motion of the electrode improved the material removal rate and the volumetric wear ratio, reduces the overcut and enables the drilling of deep holes.

Paper (International Journal of Electrical Machining, No.11, 2006, pp.15-18)

Planetary EDMCross section of drilled hole

EDM of Reverse-Tapered Microholes
The EDM of reverse-tapered microholes with a diameter of less than 100 Ám and a high rate of taper. A hole 50 Ám in entrance diameter and 115 Ám in exit diameter was fabricated.

Paper (Proceedings of The 3rd International Conference on Leading Edge Manufacturing in 21st Century (LEM21), 2005, pp.757-760)

Tool electrode with the middle part thinner than the other partsBent tool electrode

EDM of Reverse-Tapered Microholes Using Bent Electrodes
EDM of reverse-tapered microholes has been attempted using bent tool electrodes. Holes with a diameter of less than 100 Ám and a cone angle of up to 90 degrees were successfully drilled. This technique was also used to chamfer one opening of a hole from the opposite opening.

Paper (International Journal of Electrical Machining, No.13, 2008, pp.15-20)

Cross section of drilled holeChamfered hole

Strength Evaluation of Eectrical Discharge Machined Micropins and Application to Fabrication of Ultrasmall-Diameter Cutting Tools
The bending strength of cemented tungsten carbide 10-Ám-diameter micropins fabricated by micro EDM was investigated. Although the bending strength increased with a decrease in the electrical discharge energy at the finish machining of micropins, it decreased at lower discharge energy. This result was then applied for the EDM fabrication of cemented tungsten carbide ultrasmall-diameter cutting tools.

Paper (Journal of Japan Society for Abrasive Technology, Vol.56, No.6, 2012, pp.395-399)

Relationship between open-circuit voltage at finish machining and bending strength of micropinsRelationship between open-circuit voltage at finish machining and tool life

Return to Page Top

| Return to Previous Page |