A comparative analysis of welded al-6061 sheet joined by MIG and TIG welding methods

Abstract

The present work deals with the assessment of tensile strength, hardness, and microstructural changes in welded Al 6061 plates. Based on that, the performance of two different welding techniques- metal inert gas welding (MIGW) and tungsten inert gas welding (TIGW) has been compared. All the sheets were having a thickness of 3.0 mm. MIG welding has been done with a filler wire also same filler metal has been applied during TIG welding for comparing the results. Tensile samples were prepared as per ASTM-E8/E8M-09 Standard from the MIG welded specimens. Tensile test was made using Universal Testing Machine (UTM) with hydraulic grip. The microstructure of all the specimens were carried out using Metallurgical microscope with Image Analyzer System, the Microhardness study was carried out using Digital Vickers Microhardness tester. The primary phase (bright Al-grains) of the base metal zone (BM) with thin solid boundary has changed into thick dendritic shapes in the welded zone (WZ). Also, the coarse secondary phase of BM has converted into fine particles in WZ under the influence of rapid cooling. The WZ has been reported harder than HAZ in MIG and TIGW Sheet has been found harder than WZ due to the accumulation of fine equiaxed secondary phase.