Temperature Field Of Tig Arc Based On Fowler-Milne Method

In the past, traditional welding research is about the welding processparameters, such as current and voltage, instead of its internal physicalproperties as a special plasma. This paper is mainly to take the DC/Pulse TIGarc as the objects to study arc plasma thermodynamic parameters andanalysis internal transport process by arc plasma spectrum diagnosis theory.Set up spectral acquisition system based on the spectrometer and higharc image acquisition system based on CCD speed camera. First, the DC TIGarc temperature field is from12K-22K with the Boltzmann mapping methodand the standard temperature method (ArI:794.8nm); And Boltzmannmapping method is relatively simple and fast, but in time resolution andspace resolution, standard temperature is better; Second, use Starkbroadening method and Saha equation method to measure DC TIG arc, itselectronic density distribution is1022-1023(m-3). According to localthermodynamic equilibrium criterion, it’s prove that DC TIG arc (200A) islocal thermodynamic equilibrium. At last, taking the pulse TIG arc as the research object, use standardtemperature meathod to measure its peak value (base value) arc temperaturefield; During the peak-base (base-peak) transition time, arc temperature lagsbehind current changes (less than1ms); Arc frequency (1Hz-500Hz) changeshas no effect on its thermodynamic state.With the research of DC/Pulse TIG arc temperature field and electrondensity，this paper enrich the spectral method diagnostics application in thewelding area, and provide for theory for welding quality control.