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Electrical Conductivity of Dielectric on WEDM Characteristics

WEDM 가공특성에 대한 방전액의 전기전도율의 영향

  • 김창호 (동의대학교 기계산업시스템공학부) ;
  • 여홍태 (동의대학교 기계산업시스템공학부 기계공학과)
  • Published : 2003.10.01

Abstract

This work deals with the electrical conductivity of dielectric on output parameters such as metal removal rate and surface roughness value of a carbon steel(SM25C) and sintered carbides cut by wire-electrical discharge machining(W-EDM). Dielectric has several functions like insulation, ionization, cooling, the removal of waste metal particles. The presence of minute particles(gap debris) in spark gap contaminates and lowers the breakdown strength of dielectric. And it is considered that too much debris in spark gap is generally believed to be the cause of arcing. Experimental results show that increases of cobalt amount in carbides affects the metal removal rate and worsens the surface quality as a greater quantity of solidified metal deposits on the eroded surface. Lower electrical conductivity of the dielectric results in a lower metal removal rate because the gap between wire electrode and workpiece reduced. Especially, the surface characteristics of rough-cut workpiece and wire electrode were analyzed too. Debris were analyzed also through scanning electron microscopy(SEM) and surface roughness tester. Micro cracks and some of electrode material are found on the workpiece surface by energy dispersive spectrometer(EDS).

Keywords

Wire Electrode;Electrical Conductivity;Dielectric;Metal Removal Rate;Sintered Carbide

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