Effect of pulsed current GTA welding parameters on the fusion zone microstructure of AA 6061 aluminium alloy

2007 ◽  
Vol 13 (4) ◽  
pp. 345-351 ◽  
Author(s):  
T. Senthil Kumar ◽  
V. Balasubramanian ◽  
S. Babu ◽  
M. Y. Sanavullah
Keyword(s):  
Aluminium Alloy ◽  
Fusion Zone ◽  
Gta Welding ◽  
Welding Parameters ◽  
Pulsed Current ◽  
6061 Aluminium Alloy ◽  
Zone Microstructure

Enhanced Mechanical Properties of AA5083 GTA Weldments with Current Pulsing and Addition of Scandium

2013 ◽  
Vol 765 ◽  
pp. 716-720 ◽  
Author(s):  
N. Kishore Babu ◽  
Patil Yogesh Bhikanrao ◽  
K. Sivaprasad
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fusion Zone ◽  
Weld Zone ◽  
Solidification Structure ◽  
Grain Structure ◽  
Welding Parameters ◽  
Pulsed Current ◽  
Current Technique ◽  
Aa5083 Alloy

AA5083 alloy is welded with gas tungsten arc welding using optimized welding parameters. Al-Si-Sc master alloy filler with varying contents of scandium is used for welding. Welding was carried out with and without AC-pulsed current techniques. A narrow heat affected zone with more refined grain structure is observed in the case of the pulsed current technique. Furthermore, it is observed that the columnar solidification structure in the fusion zone was suppressed and fine equiaxed grains were formed in the weld zone with increasing scandium content, which is attributed to the grain refinement effect of scandium with the generation of increased nucleating sites during weld solidification. This effect is reflected in mechanical properties also. An increased hardness of about 10 % results with pulsed current technique compared to about 20 % with an addition of 0.75 % scandium. However, in the case of tensile properties pulsing resulted in about 8 % increase in tensile strength and addition of 0.75 % scandium resulted in about 40 % increase in tensile strength. Both the pulsed current technique and the addition of scandium were observed to be better in increasing not only strength but also elongation due to the refined grain structure in the weld fusion zone.

Effect of Pulsed Current Gas Tungsten Arc Welding Parameters on Microstructure of Titanium Alloy Welds

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
M. Balasubramanian ◽  
V. Jayabalan ◽  
V. Balasubramanian
Keyword(s):  
Grain Size ◽  
Titanium Alloy ◽  
Weight Ratio ◽  
Gta Welding ◽  
Pulse Frequency ◽  
Welding Parameters ◽  
Pulsed Current ◽  
Thin Sections ◽  
Gas Tungsten Arc ◽  
Gas Tungsten

Titanium is one of the most important nonferrous metals, which finds extensive application in aerospace and chemical industries, because of its light weight, excellent corrosion resistance and high strength to weight ratio. Single pass gas tungsten arc (GTA) welding of thin sections of Ti–6Al–4V was accomplished with pulsing current technique and was found to be superior to conventional continuous current process in terms of grain refinement in the fusion zone. In this investigation, an attempt was made to study the effect of pulsed current GTA welding parameters on titanium alloy weld characteristics such as grain size and hardness. It was revealed that at an optimum value of 6 Hz pulse frequency and 80A peak current, the hardness was maximum and the grain size was minimum. Pulsing current in inert gas welding was found to be beneficial in titanium welding.

Laves Phase Control in Inconel 718 Weldments

2012 ◽  
Vol 710 ◽  
pp. 614-619 ◽  
Author(s):  
S.G.K. Manikandan ◽  
D. Sivakumar ◽  
M Kamaraj ◽  
K. Prasad Rao
Keyword(s):  
Solid Solution ◽  
Fusion Zone ◽  
Inconel 718 ◽  
Welding Process ◽  
Gta Welding ◽  
Phase Control ◽  
Laves Phase ◽  
Filler Wire ◽  
Shielding Gas ◽  
Zone Microstructure

The detrimental laves formation in fusion zone during welding of Inconel 718 is controlled with compound current pulsing technique along with helium shielding gas. Also solid solution filler wire is used to minimize the niobium segregation. Welds were produced in 2mm thick sheets by GTA welding process and subjected to the characterization techniques. The results show, refined fusion zone microstructure, reduced amount of laves phase, minimum niobium segregation and softer fusion zone in the as welded condition.

The Influence of Gas Tungsten Arc Welding Parameters on Mechanical and Microstructure Properties of the TC4 Titanium Alloy

2019 ◽  
Vol 969 ◽  
pp. 895-900 ◽  
Author(s):  
Muralimohan Cheepu ◽  
D. Venkateswarlu ◽  
P. Nageswara Rao ◽  
S. Senthil Kumaran ◽  
Narayanan Srinivasan
Keyword(s):  
Titanium Alloy ◽  
Fusion Zone ◽  
Welding Speed ◽  
Welding Parameters ◽  
Bead Geometry ◽  
Box Behnken Design ◽  
Gas Tungsten Arc ◽  
Tc4 Titanium Alloy ◽  
Gas Tungsten ◽  
Zone Microstructure

In the present study, TC4 titanium alloy was gas tungsten arc welded to evaluate the mechanical and metallurgical properties of the welds. The welds were carried out at different welding conditions such as welding speed and current to identify their effect on microstructural changes and strength of the welds. The results of bead geometry measurements suggests that the fusion zone width and depth was greatly varying with the welding speed and current. It is also observed that the fusion zone microstructure and heat affected zones are greatly controlled by welding conditions. Therefore the mechanical properties of the welds were improved with the changes in welding conditions and are correlated with the metallurgical features of the welds. The optimal welding conditions were analysed using Box-Behnken design and analysis of variance technique for identifying strength of the welds and better bead geometry parameters.

COMPARISON STUDY ON PULSED AND ARC OSCILLATION TECHNIQUES OF GTA WELDED AZ31B MAGNESIUM ALLOY JOINTS

2019 ◽  
Vol 14 (4) ◽  
Author(s):  
Subravel V ◽  
Asaithambi B
Keyword(s):  
Magnesium Alloy ◽  
Tensile Properties ◽  
Fusion Zone ◽  
Automobile Industry ◽  
Gta Welding ◽  
Pulsed Current ◽  
Az31b Magnesium Alloy ◽  
Fuel Savings ◽  
Gas Tungsten Arc ◽  
Lightweight Metals

The challenges of achieving significant weight reduction in the automobile industry in the context of fuel savings, recyclability and emission reduction has promoted focus on lightweight metals such as magnesium. GTA welding technology is the main welding method adopted for magnesium alloys because of its advantages of utility and economy. Both magnetic arc oscillation and current pulsing techniques resulted in significant microstructural refinement in weld fusion zone. Hence in this investigation an attempt has been made to study the arc pulsing and arc oscillation on tensile and microstructural characteristics of pulsed current gas tungsten arc welded AZ31B magnesium alloy joints. From this investigation, it is found that the joints fabricated with magnetic arc oscillation having the superior tensile properties compared to pulsed current welding. The formation of fine grains and higher hardness in fusion zone are the main reasons for the superior tensile properties of these joints

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