Understanding the factors critical to the TIG welding of Cu components in bar wound electric motors

Abstract

Developing robust manufacturing processes for electric traction motors is essential to support GM's electrification roadmap. When assembling an electric motor, many copper components in the form of wires, bars, and bus rings are joined together. The joints must be highly conductive to achieve high efficiency as well as mechanically strong to survive the harsh service environment. A potential joining method that could meet the above-mentioned requirements is tungsten inert gas arc welding (TIG). TIG welding offers the highest energy density compared with other arc welding processes and requires far less capital investment compared with laser and electron beam welding. In this report, we will four factors critical to the welding process, namely: the type of shielding gas, weld current, electrode to workpiece distance, and weld time; and how each factor influences the weld quality.