Heat transfer characteristics of graphite welding pool in penetration brazing of Cu/Ni dissimilar metal wires

Abstract

In order to discuss the heat transfer characteristics of the graphite welding pool and the copper electrode, in penetration brazing of Cu/Ni dissimilar metal wire. A mathematical model for electrothermal coupling, on penetration brazing of Cu/Ni dissimilar metal wire, is developed, to describe temperature distribution and influence factors of different types of graphite welding pool and copper electrode, using simulation and experimental tests. The simulation results show that temperatures of the common graphite welding pool is 749.88°C, while the experimental results show that temperatures of the common graphite welding pool is 752.23°C, and the corresponding temperature range of the copper electrode is 236.5°C to 752.23°C, respectively. Furthermore, the length of the copper electrode at high temperature is 16 mm. Since the common graphite has the lowest thermal conductivity, higher thermal resistance, at the contact interface, is developed, while the contact heat, transferred to electrode, is reduced. Last, the heat transfer effect of the common graphite is stronger than that of fine graphite, isostatic graphite and molded graphite.