Experimental investigation of pug cutter embedded TIG welding of Ti-6Al-4V titanium alloy

Abstract

Light-weight materials, such as titanium alloy, have been extensively investigated. This paper primarily focuses on microstructural, metallurgical, and mechanical properties of the pug cutter embedded tungsten inert gas (TIG) welding of Ti-6Al-4V titanium alloy. In this work, TIG welding was modified to control the speed and the arc length. Analysis revealed that the microstructure underwent severe changes at different zones: coarsened in the fusion zone (FZ) and enlarged in the heat-affected zone (HAZ). The microstructure was finer at the base metal than those in the FZ and the HAZ, and the Vickers hardness values decreased from weld center line to the base metal. Tensile test showed that the specimen with low current and high speed was broken below its ultimate tensile strength, whereas most of the samples were broken at the base metal region that had a similar strength to that of the parent metal. The elongation of the metal was primarily affected by the heat input. A high volume of heat increased the hardness and the brittleness, resulting in low ductility.