Arc Control And Spectral Analysis Of TIG Welding On Nickel-based Alloys

In this article the arc control of the J-shaped groove automatic TIG weldingsystem is described, complete the design of the hard ware circuit in the control system.The hardware circuit includes a data acquisition channel, which captures the real-timewelding current and arc voltage signal using the sensor; also includes an outputchannel, which controls the current output of the welding power and the speed of wirefeed by outputting the corresponding voltage. In addition, design the soft of arccontrol system, write the data acquisition system module, which stores and displaysthe signal collected by the data acquisition channel; write the welding arc controlmodule, which outputs the voltage analog signal an control the welding current andwire feed speed through the output channel.In order to understand the characteristics of the arc of the TIG welding, study theimpact of the welding parameters and the material of workpiece on the arc in the caseof DC. Two sets of experiments is designed, undergo TIG welding with differentwelding current and arc length on the workpiece, and collect the arc spectrum duringthe welding processes. First, complete the TIG welding tests with the differentwelding current, and analysis the arc spectrum, the results shows the electrontemperature doesn’t change much in the different welding processes and is alwaysaround11000K, and the electron density increases gradually with increasing current.then undergo the TIG welding tests with the different arc length, the results shows theelectron temperature change little in the different welding processes, while theelectron density decreases along with the growth of the arc length.In order to study the difference of the arc between the peak current and basecurrent, design DC pulse TIG welding tests with different welding current andanalysis the arc spectrum. The results showed that in the same welding process, theelectron temperature of the peak current is slightly higher than the electrontemperature of the base current, but the difference is little, and the electron density ofthe peak current is higher than the electron density of the base current.Compared with the DC TIG welding processes, the electron density of the DCpulse TIG welding processes is higher with the same welding parameters.