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Four Properties Of Graphite Electrodes

Pulished on Dec. 28, 2019

For graphite materials, the following four indicators directly determine the performance of the material:

The average particle diameter of the material:

The average particle diameter of the material directly affects the condition of the material discharge. The smaller the average particle size of the graphite material, the more uniform the discharge of the material, the more stable the discharge condition, the better the surface quality, and the smaller the loss; the larger the average particle size, the higher the removal rate can be obtained in rough machining, but the finished surface The effect is poor, and the electrode loss is large.

Bending strength of the material:

The flexural strength of a material is a direct reflection of the strength of the material and shows how tight the internal structure of the material is. Materials with high strength have relatively good discharge resistance. For electrodes with high accuracy requirements, choose materials with higher strength as much as possible.

Shore hardness of material:

The hardness of graphite is higher than that of metal materials, and the wear of the tool during cutting is greater than that of cutting metal. At the same time, graphite materials with high hardness have better control of discharge loss.

Material's inherent resistivity:

A graphite material with a large specific resistivity will have a slower discharge rate than a small resistivity. The higher the specific resistivity, the smaller the electrode loss, but when the specific resistivity is higher, the stability of the discharge is affected.

China graphite electrode manufacturer has many different grades of graphite to choose from. Generally classified according to the average particle diameter of graphite materials, particle diameter ≤ϕ4 μm is defined as fine graphite, particle diameter between ϕ5 ~ ϕ10 μm is defined as medium graphite, and particle diameter above 10 μm is defined as coarse graphite. The smaller the particle diameter, the more expensive the material. You can choose a suitable graphite material according to the requirements and cost of EDM.

Production of china graphite electrode:

The graphite electrode in the mold manufacturing is mainly completed by a milling process. From the perspective of processing technology, graphite and copper are two different materials, and they should master their different cutting characteristics. If a graphite electrode is processed using a copper electrode process, problems will inevitably occur. For example, the sheet often breaks, which requires the use of appropriate cutting tools and cutting parameters. The graphite electrode processing tool wears more than the copper electrode. In terms of economy, it is the most economical to choose a carbide tool. It is more expensive to choose a diamond-coated tool (called a graphite knife), but the diamond-coated tool has a long service life. High processing accuracy and good overall economic benefits. The size of the rake angle of the tool also affects its service life. A tool with a rake angle of 0 ° will have a service life that is up to 50% longer than a tool with a rake angle of 15 °. The cutting stability is also good, but the larger the bevel, the more The better the surface quality, the best surface quality can be achieved with a 15 ° bevel tool. The cutting speed during processing can be adjusted according to the shape of the electrode, usually 10 m / min. Similar to the processing of aluminum or plastic, the tool can be directly placed on the workpiece during rough machining, and the phenomenon of chipping and chipping is easy to occur during finishing. , Often using a light knife and brisk walking..

Graphite Electrode

Graphite Electrode

Graphite electrodes generate a large amount of dust during cutting. To avoid graphite particles being drawn into the machine tool spindle and lead screw, there are currently two solutions: one is to use a special graphite processing machine, and the other is to use an ordinary machining center. Retrofit, equipped with a special vacuum cleaner. Special graphite high-speed milling machines on the market have high milling efficiency, can easily complete the manufacture of complex electrodes, high electrode accuracy, and good surface quality.

If you need to use graphite wire electrode to make graphite electrode, it is recommended to use fine graphite material with smaller particle diameter. Graphite materials have poor EDM processing performance. The smaller the particle diameter is, the higher the cutting efficiency can be, avoiding abnormal problems such as frequent broken wires and surface streaks.