Welding of graphite electrode to copper wire

Instructor: Mr. Bai Jinsheng, Deputy director/chief expert of Special Welding Service Center of China National Defense Technology and Industry, distinguished professor/professional leader of Tianjin Sino-German University of Applied Technology. 1. Question raising Energy Institute of Tianjin Sino-German University of Applied Technology developed China’s special weapons and equipment, and encountered mechanical connection between graphite electrode and copper wire. Due to long-term strong vibration, there was a hidden danger of loosening at the connection that should not be allowed. Graphite electrode is nonmetal, copper wire is metal. Before that, they couldn’t be permanently fused together. After consulting many domestic and foreign materials, no record of this welding technology has been found. With the development of The Times and the progress of science and technology, forcing welding technology from metal welding to non-metal welding development. We invent. Dare to be the first, and then to the metal and non-metal welding efforts, and constantly extend the new welding technology. 2: difficulties of welding 2.1: No relevant welding technical information has been found at home and abroad. 2.2: There is no reference to the basic data, only graphite surface oxidation in air 200°, not only welding is not easy, also not easy to bond. 3: Challenge the impossible We have collected a large number of relevant information, after repeated experiments, the courage to explore innovation. In the conventional experiment: graphite electrode and any metal can not be welded, for graphite 200° oxidation phenomenon, we found in the temperature of 1000℃ above, under vacuum conditions, or inert gas protection: graphite electrode appeared infiltration, there is the possibility of metal and non-metal integration. 4. Experimental means 4.1: Vacuum method is adopted to remove the oxide layer on the surface of graphite electrode at 1000* c and surfacing silver steel brazing material. 4.2: Using laser (special cleaning) method, surfacing of copper and silver alloy above 1000°C. 4.3: Surfacing copper-silver alloy at high temperature above 1000℃ (inert gas protection). 4. 4: Natural cooling. 4. 5: Using soldering iron brazing method, it is easy to dissolve copper wire and silver copper material on graphite, and ensure its welding quality, without any loss. 5: post-welding detection 5.1: Metallographic 500 times to see the weld fusion ratio. 5.2: Mechanical test, all welded joints are broken on the base material (graphite electrode peeling or copper wire pulling) after destructive test. 5.3: Conductivity is higher than graphite and copper wire (welding material is silver copper solder). Comparison of conductivity: graphite conductivity is 6.5, copper conductivity is 57, silver steel conductivity is (57-63). 6: conclusion Our new welding technology of graphite electrode and steel wire is the first of its kind in the world and fills the gap in the world. This once thought impossible has been successfully challenged by us, which has made special contributions to China’s national defense construction and economic development.铜焊丝,Copper Welding Rods,铝焊丝,aluminium welding wire,镍焊条,Nickel electrode,药皮焊条,Flux Coated Brazing Welding Rods