EDM EDM Profile
author: time:2014-02-25 source:
EDM EDM belongs to a class referred to machining . Is a replication molding process , mainly for mold processing , machining
industries. The principle is put into the workpiece in a dielectric liquid between an electrode and the workpiece subjected to
20kv AC voltage by continuous discharge during a short time , the excess material is etched away .
Each successive pulse , and the electrode causes a small portion of the workpiece material is heated to melting or vaporization
temperature , and then the melted part is removed from the work area through a power or mechanical force , so that the two
electrodes will produce a crater , the size and shape of the energy spark crater about , so you can give the rough and full repair
distinction processed . A large number of pulse arc processed surface can be accurately formed pit structure and a matte surface
roughness and the special marks are not directly processed . We can use liquid jet electrolytic solution will clean up the debris
cleared and the pulse from the pulse deposited in the container gap . The workpiece and machine tool depending on the
combination of polarization , the polarization can be the result of several plant materials, the maximum amount of the volume
of cutting machining on the workpiece .
For all the good electrical conductor , if it is also a good thermal conductivity , it can be used as an electrode . In most cases ,
these materials have a sufficiently high degree of melting , so that the machine can prevent the rapid wear of the electrode .
Electrode may be turning, milling , planing, grinding , hot and cold forming, flame spraying method or solution deposition
processing. The specific approach used , the shape of the electrode depends on the accuracy requirements and the materials used .
Injection mold surface due to its high quality requirements , erosion electrodes and , in use, so in the processing of the cavity
should be used several electrodes , such micro- erosion machining ability to copy control 1um or less, its roughness 0.1um.
This manufacturing process using a mold is usually only the final polishing. In some cases , however , only with this process is
insufficient , particularly mold must withstand heavy or must be the case particularly when the surface is etched .
When spark erosion , due to thermal changes in the surface structure , the outer surface of cementite appears concentrated so
that the center between the surface layer and the intermediate layer to produce a structure . The results of structural changes in
the surface layer to produce a high residual tensile stress , which will cause cracks , and the additional surface treatment is
not necessary . Due to corrosion of the melt is almost no effect of such a surface layer , so this is not the etching surface.
These drawbacks can be prepared by reducing the tempering temperature of the heat treatment approaches the workpiece .
EDM technology in today's mold industry has occupied the position can not be ignored , it can not be processed at the processing
or difficult to process using conventional processing methods in the steel block and sintered metal complex in shape, size,
explicitly choose to use electrodes can mold manufacturing costs 40% less than conventional manufacturing method