1. The flexural strength of the material

The flexural strength of a material is a direct reflection of the strength of the material, showing the tightness of the internal structure of the material. High-strength materials have relatively good discharge wear resistance. For electrodes with high precision requirements, try to choose materials with better strength.

2. Shore hardness of the material

In the subconscious understanding of graphite, graphite is generally regarded as a relatively soft material. However, the actual test data and application conditions show that the hardness of graphite is higher than that of metal materials. In the special graphite industry, the common hardness testing standard is the Shore hardness measurement method, and its testing principle is different from that of metals. Due to the layered structure of graphite, it has quite superior cutting performance in the cutting process, the cutting force is only about 1/3 of that of copper material, and the surface after machining is easy to handle.

However, due to its high hardness, when cutting, the loss of the tool will be slightly more significant than that of cutting metal tools. At the same time, materials with higher hardness have better control over discharge loss. In our EDM material system, there are two materials to choose from for materials with the same particle size that are widely used, one with a slightly higher hardness and the other with a slightly lower hardness, to meet customers' needs with different requirements needs. The main reason is to consider the preference of various customers for electrical discharge and machining.

3. The average particle diameter of the material

The average diameter of a material directly affects the conduction of the material. The smaller the average particle size of the material, the more uniform the discharge, the more stable the discharge, and the better the surface quality.

For forging and die-casting molds that do not require high surface and precision, it is usually recommended to use materials with coarser particles; for electronic molds that require high surface and precision, it is recommended to use materials with an average particle size of less than 4 μm to ensure the fineness of the processed mold, precision, surface finish. The smaller the average particle size of the material, the smaller the loss of the material and the greater the force between the ion clusters.

At the same time, the larger the particles, the faster the discharge, and the smaller the loss of rough machining. The main reason is that the current intensity of the discharge process is different, resulting in different energy levels of the discharge. But the surface finish after discharge also varies with the particles.

4. The intrinsic resistivity of the material

According to our company's statistics on the characteristics of materials, if the average particles of the materials are the same, the discharge speed of the material with a large resistivity will be slower than that of a material with a small resistivity. For materials with the same average particle diameter, the strength and hardness of the material with low resistivity will be slightly lower than that of the material with high resistivity. That is, the rate of discharge and loss vary. Therefore, it is very important to select materials according to the needs of practical applications.

Due to the particularity of powder metallurgy, each parameter of each batch of material has its representative value with a certain fluctuation range. However, the discharge effect of graphite materials of the same grade is quite close, and the difference in application effect caused by various parameters is relatively small compared with graphite materials. The choice of electrode materials directly affects the discharge effect. It determines the discharge speed, machining accuracy, and surface roughness.

That's all. Mastering the above content will be of great help to us in identifying the grade of graphite materials. Welcome to consult us.