A comparative study of electrochemical corrosion behavior in laser and TIG welded Ti-5Al-2.5Sn alloy

Shamir, Muhammad and Junaid, Massab and Khan, Fahd Nawaz and Taimoor, Aqeel Ahmad and Baig, Mirza Nadeem (2019) A comparative study of electrochemical corrosion behavior in laser and TIG welded Ti-5Al-2.5Sn alloy. Journal of Materials Research and Technology, 8 (1). pp. 87-98. ISSN 2238-7854 (https://doi.org/10.1016/j.jmrt.2017.09.006)

[thumbnail of Shamir-etal-JMRT-2017-A-comparative-study-of-electrochemical-corrosion-behavior in-laser-and-TIG-welded]
Preview
Text. Filename: Shamir_etal_JMRT_2017_A_comparative_study_of_electrochemical_corrosion_behavior_in_laser_and_TIG_welded.pdf
Final Published Version
License: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 logo

Download (4MB)| Preview

Abstract

Corrosion behavior of TIG and laser welded Ti-5Al-2.5Sn alloy was compared using different electrochemical techniques. Bead on plate (BoP) configuration was used for welding of 1.6 mm thick Ti-5Al-2.5Sn plates which led to the formation of complete α′ martensitic structure in laser welds and acicular α along with α′ martensite within coarse prior β grains was observed in TIG welds. Potentiodynamic and cyclic polarization were carried out in 5, 7 and 9 M HNO 3 to study the effect of concentration on the galvanic corrosion of laser and TIG welded Ti-5Al-2.5Sn. The oxide layer developed after 192 h of immersion in fuming HNO 3 was studied using electrochemical impedance spectroscopy (EIS) and SEM. All the samples showed good passivity but different oxidation behavior was observed mainly because of the surface modification after the welding operation.