Because of its characteristics of light weight, high resistance to high current and low electrode wear, it is very suitable for the manufacture of precision molds in the automotive industry, and the electrode graphite is one of the development trends of the discharge machining technology.
Graphite electrode has the advantages of easy processing, high metal removal rate, small graphite loss, therefore, more and more die plant to abandon the copper electrode and switch to graphite electrode. Also some of the shapes of the electrode made of copper, but graphite is easy molding and copper electrode is heavy, not suitable for processing large electrodes, these factors have accelerated the graphite electrode in the mold manufacturing industry is more and more extensive application.
Mold factory by the copper electrode conversion of graphite electrode, first of all should be clear about the how to use graphite materials and consider other relevant factors.
Graphite is divided into different levels, in particular applications using appropriate levels of graphite and machine parameters to achieve the ideal processing effect, if the use of graphite electrode machine operators use with copper electrode of the same parameter set, then the result must be disappointing, because the melting point of copper is 1083 DEG C, and graphite in 1083 DEG C will sublimate. Therefore, graphite electrode can withstand greater machine setting conditions. If the material of the electrode is strictly controlled, the graphite electrode can be arranged in the non loss state (less than 1%) in the rough machining, but the copper electrode is not used.
The graphite electrode is easy to process, for example, the processing speed of the milling process is 2 to 3 times faster than that of the other metal processing, and the copper electrode is needed to be worn. Similarly, if the use of high-speed machining center made of graphite electrode, the speed will be faster, more efficient, but also will not produce dust problems. In these processes, the choice of the appropriate tools and graphite can reduce the wear and tear of the tool and the damage of the electrode.
The design of graphite electrode is also different. Many mold factory usually in copper electrode of rough machining and finish machining with different amount of reserve, and graphite electrode using the same amount of reserved. This reduces the number of CAD / CAM and machine processing, for this reason alone is sufficient to improve the accuracy of the mold cavity in a large extent.
Today, most of the plastic products are processed using a special grade of graphite to EDM, which eliminates the mold cavity polishing and chemical polishing process is still able to achieve the desired surface finish. Without increasing the time and polishing process, the copper electrode can not produce such a workpiece. Comparison of graphite electrode and the copper electrode milling time compared to copper electrode fast 67%, under the general situation of electrical discharge machining by the processing of graphite electrode than the copper electrode fast 58%, the processing time is reduced significantly, but also reduce the manufacturing cost.
There are many advantages of the whole graphite electrode discharge machining. Therefore, many mould factories are now being gradually converted to EDM processing of graphite electrodes in order to improve the competitiveness of enterprises and products in the market.