Effect of pulsation in TIG welding on the microstructure, residual stresses, tensile and impact properties of Ti-5Al-2.5Sn alloy. (April 2021)

• Record Type: Journal Article
• Authors: Khan, Fahd Nawaz; Junaid, Massab; Hassan, Ali Abdelhafeez; Baig, Mirza Nadeem
• Is Part Of: Proceedings of the Institution of Mechanical Engineers. Volume 235:Number 2(2021)
• Page Start: 361
• Page End: 370
• Publication Date: 2021-04
• Subjects: Titanium alloys -- tungsten inert gas welding -- grain boundaries -- residual stress -- microstructure -- impact toughness; Mechanical engineering -- Periodicals; Production engineering -- Periodicals; Manufacturing processes -- Periodicals; 621.05
• DOI: 10.1177/0954408920964689
• Languages: English
• ISSNs: 0954-4089

Abstract

Pulsation of current is widely employed in Tungsten Inert Gas (TIG) welding of titanium alloys. In the current study, the influence of welding speed and welding currents (peak and background) on the properties pulsed TIG welded Ti-5Al-2.5Sn alloy were investigated. The weldment characteristics which were analyzed included weld zone size, microstructure, residual stresses, tensile and impact properties. Increasing the welding speed and gradient of pulsed current enhanced grain strengthening in the fusion zone (FZ) which was attributed to increased cooling rate. Such a welding condition was also favorable in achieving full penetration weldments with a reduced; heat affected zone width, grain size in FZ and residual stresses. However, a tensile strength superior to the base metal was observed. The impact toughness reduced by increasing the pulsed current gradient and a high value of both peak and background currents were required to improve the impact toughness of the weldments.