TIG arc-induced non-contact MIG arc ignition

Abstract

Based on recorded arc images, the metal inert gas (MIG) arc ignition process is analyzed and the effects of different tungsten inert gas (TIG) welding parameters on MIG arc ignition are investigated. The TIG arc induces the non-contact ignition of the MIG arc because a filamentary discharge channel develops from the MIG wire end to the TIG arc, causing the electrical breakdown of the gap between them. Among TIG welding parameters, the TIG welding current and tungsten-wire spacing are considered the main factors affecting the non-contact MIG arc ignition because changing them has a relatively greater impact on the ease of non-contact MIG arc ignition. The gap breaks down at low MIG no-load voltage because the MIG wire end has a higher electric potential than the TIG arc, a strong electric field region exists near the MIG wire end, and the MIG wire can be fed toward the workpiece.