Are EDM and WEDM the same concept?

Not a concept. EDM machine tools are specifically divided into EDM machine tools and WEDM machine tools. The machining principle is the same, which uses the high temperature generated by the contact discharge between the positive and negative electrodes of the current to melt the metal, thus achieving the purpose of cutting.

WEDM is divided into fast line and wire cutting. As the name implies, it is distinguished according to the speed of electrode wire movement. Molybdenum wire is generally used as the electrode wire of fast moving wire. The machining efficiency is relatively high and the precision is low.

Wire cutting uses copper wire as electrode wire, which has low machining efficiency and high precision, and generally needs to be cut 3-4 times. The processing cost is high. WEDM uses the reciprocating motion of electrode wires to cut parts like a saw. The disadvantage is that it can only process parts that run through from top to bottom.

Extended data:

Distinguish between fast wire cutting, medium wire cutting and wire cutting.

1:WEDM's linear speed is 6 ~ 12 mm/s, and the electrode wire reciprocates at high speed, so the cutting accuracy is poor.

2.WEDM is a new technology developed in recent years, which realizes the function of frequency conversion and multiple cutting on the basis of fast wire cutting.

3. WEDM has a linear speed of 0.2mm/s and the electrode wire moves in one direction at low speed, so the cutting accuracy is very high.

Free positive ions and electrons accumulate in the electric field and soon form ionized conductive channels. At this stage, an electric current is formed between the two plates. It leads to numerous collisions between particles, forming plasma, which quickly rises to the high temperature of 8000 to 12000 degrees, instantly melting some substances on the surfaces of the two conductors.

At the same time, due to the vaporization of electrode and dielectric liquid, bubbles are formed, and their pressure rises regularly until it is very high. Then the current is interrupted, and the temperature drops suddenly, so that the bubbles explode inward, and the generated power throws the dissolved substances out of the crater, and then the corroded substances re-condense into small balls in the dielectric liquid and are discharged by the dielectric liquid.

Then through the monitoring of numerical control and the execution of servo mechanism, this discharge phenomenon is uniform.

Reciprocating WEDM has certain advantages. At the same time meet the needs of domestic and foreign customers. The number of such machine tools is increasing at a rapid speed, from the original annual output of 2-3 thousand to tens of thousands, and the stock of reciprocating wire cutting machines in China has reached more than 200 thousand.

It has become one of the most widely used types of CNC machine tools in China. However, because the reciprocating WEDM can't control the constant tension of the electrode wire, the electrode wire fluctuates greatly during machining and is easy to break. Because of the repeated use of electric grade wire, it will cause the loss of electrode wire and reduce the machining accuracy and surface quality.

References:

Baidu encyclopedia -WEDM