Graphite has high high temperature strength, low therma […]
Graphite has high high temperature strength, low thermal expansion coefficient, good workability and good thermal and electrical conductivity. Therefore, graphite electrodes are widely used in metallurgy, electric furnace, electric discharge machining and other fields. Graphite itself is a very easy to cut material, but the graphite material used as an EDM electrode requires high strength. At the same time, there are many thin walls, small rounded corners, and sharp changes in the shape of the graphite electrode, which affect the grain size and strength of the graphite electrode material. All have higher requirements, which causes the graphite electrode to be easily broken during the processing, and the tool is easy to wear, which makes the graphite electrode difficult to process. Therefore, how to improve the efficiency of graphite electrode processing and reduce the cost of graphite electrode tools has become an important issue to be solved urgently in graphite electrode processing.
Research on High Speed Milling Process of Graphite Electrode
In the past, graphite electrode milling methods used a single electrode, a single clamping, a single program, and one by one. Because the electrode program time is generally relatively short, the machining personnel often stay next to the machine tool and wait for the program to end. After changing the tool, do another program. The length of the tool used for programming is also different every time, which causes the machining staff to re-clamp and set the tool every time, which increases the working hours and the error rate. One operator can only build one machine tool, which is laborious and laborious.
The optimized high-speed milling process research of graphite electrode is mainly due to the technological progress of graphite electrode processing equipment and cutting tools. From the aspect of graphite machine, for programming, it is generally necessary to know in advance which one of the workpieces to be made. It is done on the machine tool, then when the program is output after the program is completed, the machine tool can be directly selected to output the code that it can recognize, without the need for the machine operator to edit the program or let the programmer to output again. The operator now only needs to call one program, and there is no need to tune several programs as in the past, which are already connected in series during post-processing.
Diamond graphite milling cutter promotes high-speed milling of graphite electrodes
The material of graphite milling cutters affects the widespread use of high-speed milling technology. The tools currently suitable for high-speed milling include: coated graphite milling cutters, ceramic cutters, cubic boron nitride (CBN) cutters, polycrystalline diamond (PCD) cutters, etc. The choice of tool material has an important impact on processing efficiency, processing quality, processing cost and the life of graphite electrode tools. After a large number of experiments and applications, diamond graphite milling cutters are currently an ideal tool material for high-speed milling of graphite electrodes. The advantages of diamond graphite milling cutters to promote high-speed milling of graphite electrodes are as follows:
1. High hardness and wear resistance
For high-speed milling of graphite electrodes, the hardness of the tool material must be much higher than that of graphite material. The higher the hardness of the tool material, the better the wear resistance, and diamond is the hardest superhard material found so far. The wear resistance of diamond tools with particle size CDW025 and CDW302 is the best.
2. High strength and durability
Diamond tool materials have high strength and resistance, and can accept large cutting forces, vibrations and impacts. Polycrystalline diamond (PCD) tools and CVD diamond coated tools are all made of cemented carbide tools and welded on the cutting part. Or coated with diamond material, combining the high hardness of diamond and the high toughness of cemented carbide to avoid brittle fracture of the tool.
Extension: PCD tools and CVD diamond coated tools
Polycrystalline diamond PCD graphite milling cutters and CVD diamond-coated graphite tools are ideal tool choices for processing graphite materials. CVD diamond-coated graphite tools have the advantages of high hardness and good wear resistance, but the cost of diamond-coated tools has always been High, and as the production technology of PCD graphite milling cutters becomes more and more mature, the cost and price have also been reduced, so the application of PCD cutters in the field of processing graphite materials has become more and more extensive.
In general, for graphite milling cutters for micro-diameter processing, it is recommended to choose CVD diamond-coated graphite milling cutters, such as graphite ball-end milling cutters and graphite milling cutters with small micro-diameters below 3mm. Valin tool engineers recommend CVD diamond coating. Graphite end mills are more effective; for larger diameter graphite milling cutters, it is more cost-effective to choose CDW025/CDW302 polycrystalline diamond PCD graphite cutters. PCD cutters can be made into various structural forms, such as PCD turning tools, pcd drill bits , Pcd end mills, pcd ball end mills, pcd milling blades, pcd groove cutters, pcd boring cutters, etc.