438 / 2022-03-15 22:08:49

Temperature Rise Characteristics of Contact Interface of Graphite Electrode Under High Current Arc Impact Force

arc impact force;,graphite electrode;,G-W model;,contact stress;,roughness;,temperature rise

In the field of high voltage and high current impulse discharge, graphite is widely used as an electrode material because of its good anti-erosion property. Due to the heat and force of the high current arc, the contact interface of the graphite electrode is easily welded, which affects the use of the electrode. According to Hertz contact theory, the Greenwood-Williamson contact model of the contact interface between graphite electrode and metal base was established. Combined with the finite element simulation software, the temperature rise of the contact interface of graphite electrode and its influencing factors were calculated and analyzed. The research shows that the roughness, contact area, and contact stress of the graphite electrode and the metal base affect the temperature rise of the contact interface. The arc impact force affects the corresponding electrical and thermal contact characteristics by changing the real contact area between the graphite electrode and the metal base. Selecting metal base materials with high thermal conductivity, high density, high specific heat capacity, and low resistivity helps to reduce the temperature rise of graphite electrode contact interface. Selection of appropriate contact interface roughness between graphite electrode and metal base can also prevent the welding phenomenon caused by contact interface temperature rise.