rp 800 mm graphite electrodes

The application of rp 800 mm graphite electrodes in mold EDM

Application of rp 800 mm graphite electrodes in mold EDM In the 20th century, copper was widely used as the material of rp 800 mm graphite electrodes in EDM. At that time, only when manufacturing large-scale rp 800 mm graphite electrodes and mold processing requirements were not high or rough processing, graphite materials would become another consideration. Some early technicians who have been in contact with rp 800 mm graphite electrodes have a common impression: the graphite material is dirty, easy to drop off, the surface effect is not good, and the processing efficiency is not high. With the development of high and new technology, the manufacturing process of graphite materials has been continuously improved, and graphite materials that can meet different EDM requirements are emerging in endlessly. In the market, graphite high-speed milling machine tools have emerged, and the graphite discharge performance of CNC EDM machine tools has been comprehensively improved.

Today, in Europe, where manufacturing technology is leading, more than 90% of the rp 800 mm graphite electrodes used by mold companies use graphite. Graphite is widely used as the material of rp 800 mm graphite electrodes in molds for aerospace, automobiles, home appliances, electronics, etc. This significant change is due to the advantages of rp 800 mm graphite electrodes with high processing efficiency and good quality. But in my country, most mold companies still choose copper as the main material for rp 800 mm graphite electrodes. Based on the characteristics of graphite materials, the advantages and disadvantages of EDM are comprehensively analyzed, and how to choose graphite materials, rp 800 mm graphite electrodes manufacturing and EDM points are introduced, and practical application cases are provided. 2. EDM characteristics of graphite materials 2.1 EDM speed Graphite is a non-metallic material with a high melting point, up to 3650°C, while copper has a melting point of 1083°C, so rp 800 mm graphite electrodes can withstand more current Set the conditions. The larger the discharge area and the size of rp 800 mm graphite electrodes, the more obvious the advantage of efficient rough machining of graphite materials. The thermal conductivity of graphite is 1/3 of copper, and the heat generated during the discharge process can remove metal materials more effectively. Therefore, the processing efficiency of graphite is higher than that of copper rp 800 mm graphite electrodes. According to processing experience, under suitable conditions, the electrical discharge processing speed of rp 800 mm graphite electrodes is 1.5 to 2 times faster than that of copper rp 800 mm graphite electrodes. 2.2 rp 800 mm graphite electrodes loss rp 800 mm graphite electrodes have the characteristics of high current resistance.

In addition, under appropriate rough machining conditions, the carbon particles in the carbon-containing steel workpiece and the high-temperature decomposition products in the working fluid during the machining process. Under the effect of polarity, some corrosion products and carbon particles will adhere to the surface of the rp 800 mm graphite electrodes to form a protective layer, which ensures that the loss of the rp 800 mm graphite electrodes during the rough processing is very small, or even “zero loss.” The main loss of rp 800 mm graphite electrodes in EDM comes from rough machining. Although the setting conditions of finishing have a high loss rate, the total loss of parts is also very small because the machining allowance is not much, that is, the machining erosion is small. Generally speaking, the loss of rp 800 mm graphite electrodes during high-current rough machining is less than that of copper rp 800 mm graphite electrodes, and the loss of rp 800 mm graphite electrodes during finishing may be slightly larger than that of copper rp 800 mm graphite electrodes. The loss of the rp 800 mm graphite electrodes of the two rp 800 mm graphite electrodes is similar. 2.3 Surface quality The particle size of graphite directly affects the surface roughness of EDM. The smaller the diameter, the lower the surface roughness. A few years ago, when graphite material with a diameter of 5μm was used, the best surface for EDM could only reach vdi18 (Ra0.8μm). At present, the particle size of graphite materials can reach within φ3μm, and the best surface for EDM can reach vdi12 (Ra0.4μm) or finer level, but rp 800 mm graphite electrodes cannot be processed with mirror EDM. Copper material has low resistivity and compact structure, which makes it easy to obtain a stable processing state in EDM. It can be processed stably under more difficult conditions. The surface roughness is less than ra0.1μm, which can be used for mirror EDM. It can be seen that if EDM pursues a very fine surface, it is more suitable to use copper materials as rp 800 mm graphite electrodes. This is the main advantage of copper rp 800 mm graphite electrodes over rp 800 mm graphite electrodes. However, under the condition of high current solidification, the surface of copper rp 800 mm graphite electrodes is prone to roughness and even cracks, while graphite materials do not have this problem. For cavity processing with a surface roughness of vdi26 (ra2.0μm), a rp 800 mm graphite electrodes can be used to complete the process from coarse to fine, and obtain a uniform surface effect without defects on the surface.

In addition, due to the different structures of graphite and copper, the corrosion points of the surface discharge of the rp 800 mm graphite electrodes are more regular than that of the copper rp 800 mm graphite electrodes. Therefore, when processing vdi20 and above with the same surface roughness, the particle size of the workpiece surface processed by rp 800 mm graphite electrodes is more obvious, and the effect of the particle surface is better than that of copper rp 800 mm graphite electrodes.

2.4 Processing accuracy The thermal expansion coefficient of graphite materials is small, and the thermal expansion coefficient of copper materials is 4 times that of graphite materials. Therefore, compared with copper rp 800 mm graphite electrodes, rp 800 mm graphite electrodes are not easily deformed in EDM, and can obtain more stable and reliable machining accuracy. Especially in the processing of deep and narrow ribs, the local high temperature will easily cause the copper rp 800 mm graphite electrodes to bend, while the rp 800 mm graphite electrodes will not bend; for the copper rp 800 mm graphite electrodes with a relatively large depth, a certain amount of thermal expansion needs to be compensated. Value to correct the size, but rp 800 mm graphite electrodes are not required. Weight of 2.5rp 800 mm graphite electrodes The density of graphite material is less than that of copper, and the weight of an equal volume of rp 800 mm graphite electrodes is only 1/5 of that of copper rp 800 mm graphite electrodes. It can be seen that the large-volume rp 800 mm graphite electrodes are very suitable for the use of graphite materials, which greatly reduces the load on the spindle of the EDM machine tool. The rp 800 mm graphite electrodes are heavy in weight, inconvenient to clamp, and deflection and displacement may occur during processing. It can be seen that the application of rp 800 mm graphite electrodes in the processing of large molds is of great significance. 2.6rp 800 mm graphite electrodes difficult to manufacture Graphite materials have good processing performance, and the cutting resistance is only 1/4 of copper.

Under suitable processing conditions, the milling efficiency of rp 800 mm graphite electrodes is 2-3 times that of copper rp 800 mm graphite electrodes. The rp 800 mm graphite electrodes are easy to clean the angle, and the workpieces that require multiple rp 800 mm graphite electrodes can be designed as a whole rp 800 mm graphite electrodes for processing. Due to the unique particle structure of the graphite material, rp 800 mm graphite electrodes will not produce burrs after being ground. The shape is complex and difficult to remove burrs, which directly meets the requirements of use. Eliminates the manual polishing process of rp 800 mm graphite electrodes and avoids shape changes and dimensional errors caused by polishing.

It should be noted that because graphite is a dust accumulation, a large amount of dust will be generated when grinding graphite, so the milling machine must have sealing and dust suction devices. If you need to use EDM wire cutting to process rp 800 mm graphite electrodes, their processing performance is not as good as copper materials, and the cutting speed is about 40% slower than copper. 2.7rp 800 mm graphite electrodes have good adhesion when installed and using graphite materials. Using conductive glue to combine graphite with a fixture, milling and EDM can be performed on rp 800 mm graphite electrodes.

Machining screw holes on rp 800 mm graphite electrodes not only saves processing steps, but also saves processing time. Graphite materials are fragile, especially the small, narrow, and long rp 800 mm graphite electrodes, which are easily broken under external force during use, but it can be immediately known that the rp 800 mm graphite electrodes have been damaged. If it is copper rp 800 mm graphite electrodes, they will only bend and not break. They are very dangerous during use, difficult to find, and easily lead to scrapped workpieces. 2.8 Price Copper material is a non-renewable resource, and the price trend will become more and more expensive, while the price of graphite material tends to stabilize.

In recent years, the price of copper materials has continued to rise, and major graphite manufacturers have continuously improved the graphite preparation process to make it more cost-effective. Nowadays, in the same volume, the price of general-purpose rp 800 mm graphite electrodes is equivalent to the price of copper rp 800 mm graphite electrodes, but the efficient processing of graphite can save a lot of man-hours compared to the use of copper rp 800 mm graphite electrodes, which is equivalent to direct Reduce the cost of production.

In summary, among the eight characteristics of rp 800 mm graphite electrodes EDM, its advantages are obvious: milling rp 800 mm graphite electrodes and EDM efficiency are significantly better than copper rp 800 mm graphite electrodes, rp 800 mm graphite The electrodes are heavy in weight and stable in volume. The thin rp 800 mm graphite electrodes are not easy to deform, and the surface texture is better than copper. The disadvantage of graphite material is that it is not suitable for fine EDM below vdi12 (Ra0.4μm), and the wire cutting efficiency is low. However, starting from reality, an important reason that affects the effective promotion of graphite materials in my country is the need for a special rp 800 mm graphite electrodes processing machine, which puts forward new requirements for the processing equipment of mold companies, and some small companies may not have this condition.

Generally speaking, the advantages of the characteristics of rp 800 mm graphite electrodes cover most of the occasions of EDM, which are worthy of promotion and application, and have considerable long-term benefits. The use of copper rp 800 mm graphite electrodes can make up for the shortcomings of fine surface processing.