Arc characteristics and properties of a new rotating tungsten GTAW of 5A06 aluminum alloy

In this study, the rotary movement of the tungsten needle in gas tungsten arc welding (GTAW) process was realized by direct current motor. The arc characteristics, the flow of molten pool and the microstructure and properties of the weld bead were studied. The results showed that the rotary motion of the tungsten needle transferred circumferential momentum to the arc as well as the molten pool, thereby conferring the latter with rotating fluid flow characteristics. Under the action of a relatively spiraling shielding gas, arc constriction occurred, and pool width dropped considerably. A finer and more uniform precipitated phase in the matrix, as well as a fewer large-medium pores, was achieved in the 5A06 aluminum alloy weld metal using this modified GTAW process, which noticeably increased the bending strength and tensile strength of weld metal and the microhardness of fusion zone.