High-speed machining strategy of graphite electrode and optimization principle of processing parameters

Update:25-05-2019
Summary:

Graphite has high high temperature strength, low therma […]

Graphite has high high temperature strength, low thermal expansion coefficient, good processability and good heat and electrical conductivity. Therefore, graphite electrodes are widely used in metallurgy, electric furnace, EDM and other fields. In the field of EDM, the development of new graphite electrode materials and their processing technology has expanded the application range of EDM and improved its performance.

Compared with the copper electrode, the graphite electrode has the advantages of small electrode consumption, fast processing speed, good machinability, high processing precision, small thermal deformation, light weight, easy surface treatment, high temperature resistance, high processing temperature, and electrode bonding.

Although graphite is a very easy to cut material, the graphite material used as the EDM electrode must have sufficient strength to be damaged during handling and EDM processing, while the electrode shape (thin wall, small rounded corner, sharp change) Etc. also imposes high requirements on the grain size and strength of the graphite electrode, which leads to the graphite workpiece being easily broken during the processing and the tool being easily worn. Therefore, how to prevent the workpiece from collapsing, improve the surface processing quality, and reduce the cost of machining tools has become an important issue in the processing of graphite electrodes.

Conventional turning, milling, and grinding methods are often used to meet the needs of machining simple shaped electrodes, but in recent years the requirements for electrode geometry complexity have continued to increase. High-speed machining of high-machining surface quality and high machining accuracy make high-speed machining of graphite electrodes a hot spot in mold EDM processing. Many manufacturers have introduced graphite high-speed machining centers.

Due to the high-speed processing of EDM graphite electrode, it is still a new process. The processing properties of different graphite materials are also different. For the problem of workpiece crushing, tool wear and processing strategy in high-speed processing of graphite electrode, there are very few references in China. . This paper introduces the research results of high-performance graphite electrode material machining in Japan, Germany, etc., including the basic theory of cutting mechanism, cutting temperature, tool wear and chip treatment of graphite electrode materials, as well as high-speed processing strategy and processing of graphite electrode. Parameter selection and other content.