Preliminary Investigations of Structure and Properties of TIG Welded Ti-6Al-4V Alloy

Abstract

The titanium (Ti) and its alloys are taken into interest for commercial purpose due to its low density, high yield strength and high corrosion resistance properties. The present work deals with microstructural observation and mechanical property analysis of tungsten inert gas (TIG) welded Ti-6Al-4V alloys joints. For the purpose, two different set of plates were welded at same current and voltage, i.e., 190 A and 24 V, by TIG welding technique. A critical analysis into microstructure and mechanical properties like tensile strength and hardness of the welded Ti-6Al-4V plates was carried out in this work. It was found that both the plates showed different behavior during tension test. Plate 1 possessed 464.54 MPa of tensile stress and it had broken at the welded joint. Plate 2 was unaffected at welded zone but was broken at the base metal zone. The second plate consisted 501.83 MPa tensile strength. According to hardness test, both the welded plates possessed the highest hardness at the welded zone. However, plate 2 showed approximately 10% higher hardness than that of plate 2. A proper inter-relationship was observed between mechanical behavior and microstructural appearance. The microscopic view of the welded joints revealed the presence of α, β and martensitic-α phases.

Keywords

• tensile test
• tig welding
• hardness test
• ti-6al-4v titanium alloy
• microstructural analysis