Investigation of formation and microstructure of Ti-6Al-4V weld bead during pulse ultrasound assisted TIG welding

2019 ◽  
Vol 46 ◽  
pp. 241-247 ◽  
Author(s):  
Chao Chen ◽  
Chenglei Fan ◽  
Xiaoyu Cai ◽  
Sanbao Lin ◽  
Zeng Liu ◽  
...  
2019 ◽  
Vol 9 (23) ◽  
pp. 5260 ◽  
Author(s):  
Ngo Huu Manh ◽  
Nguyen Van Anh ◽  
Nguyen Van Tuan ◽  
Bin Xu ◽  
Murata Akihisa

This paper aims to develop a novel tungsten inner gas (TIG) welding torch in order to join thin sheets efficiently. Using a narrowing nozzle (constricted nozzle) inside a conventional TIG torch can critically improve the position accuracy of the tungsten electrode and also the arc plasma characteristics and heat input density. In order to evaluate the efficiency of this new torch, weld bead appearance and cross-section images were examined by an optical microscope, scanning electron microscope (SEM), and electron back scatter diffraction patterns (EBSD). The results showed that in all cases, the weld bead profile was stable without undercut and burn-through. Full penetration weld was seen. The width of weld bead on the bottom surface was increased much in comparison to conventional TIG welding. However, the results from SEM and EBSD images indicated that in the case of low welding current, the blowholes were found out on the side of the thinner material (SS400). The penetration of SUS430 material to SS400 material was not good. It seems that no fusion of SUS430 material to SS400 at the bottom surface can be seen. Meanwhile, no blowholes were seen in the case of high welding current. The penetration was better, and the fusion was reached on the bottom surface.


2014 ◽  
Vol 664 ◽  
pp. 117-121
Author(s):  
Yan Yin ◽  
Jin Guo Ta ◽  
Rui Hua Zhang ◽  
Zhan Chong Wang

Laser aided activating TIG welding was called LA-TIG. At first, the surface of weld was melted by the mini power laser protected by oxygen, and then the conventional TIG was used to cover the weld, which achieved the target of the weld with deeper penetration and narrower width. In this article, the weld bead morphology, arc images, microstructures and mechanical properties of laser aided activating TIG welding joint were analyzed. The results shows that the penetration increased significantly, excellent weld appearance and finger shape penetration were gained by laser aided activating TIG welding. It was found that the arc images of the LA-TIG was only the enlarged form compared with which observed in the conventional TIG and the arc constriction was also observed. LA-TIG weld exhibits better mechanical properties than the conventional TIG welding. Thus laser aided activating TIG welding was developed as a novel active welding method.


The characterization of weld bead deposited on low carbon steel plate with TIG welding is carried out in the present study. Three beads on plate deposits were made on a low carbon steel plate by setting the current at 75, 100 and 125 Amp, voltage at 40 Volt and the weld speed at 0.5 mm/s. The wire is fed at the rate of 2.67 mm/s. A 1.8 mm filler wire made with low carbon steel was used. The macroscopic and microscopic examination of the sample was carried out. The depth of penetration was more with respect to rise in current value for the selected weld speed. At the heat affected zone (HAZ) fine grains were seen, closer to the HAZ recrystalised grains were noted. At the base metal large ferrite grains with fine carbide particles dispersed along the grain boundaries are observed.


Author(s):  
Akash Deep ◽  
Vivek Singh ◽  
Som Ashutosh ◽  
M. Chandrasekaran ◽  
Dixit Patel

Abstract Austenitic stainless steel (ASS) is widely fabricated by tungsten inert gas (TIG) welding for aesthetic look and superior mechanical properties while compared to other arc welding process. Hitherto, the limitation of this process is low depth of penetration and less productivity. To overcome this problem activated tungsten inert gas (A-TIG) welding process is employed as an alternative. In this investigation the welding performance of conventional TIG welding is compared with A-TIG process using TiO2 and SiO2 flux with respect to weld bead geometry. The experimental investigation on A-TIG welding of ASS-201 grade shows TiO2 flux helps in achieve higher penetration as compared to SiO2 flux. While welding with SiO2 the hardness in HAZ and weld region higher than that of TIG welding process.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 981
Author(s):  
Jay Vora ◽  
Vivek K. Patel ◽  
Seshasai Srinivasan ◽  
Rakesh Chaudhari ◽  
Danil Yurievich Pimenov ◽  
...  

The Activated Tungsten Inert Gas welding (A-TIG) technique is characterized by its capability to impart enhanced penetration in single pass welding. Weld bead shape achieved by A-TIG welding has a major part in deciding the final quality of the weld. Various machining variables influence the weld bead shape and hence an optimum combination of machining variables is of utmost importance. The current study has reported the optimization of machining variables of A-TIG welding technique by integrating Response Surface Methodology (RSM) with an innovative Heat Transfer Search (HTS) optimization algorithm, particularly for attaining full penetration in 6 mm thick carbon steels. Welding current, length of the arc and torch travel speed were selected as input process parameters, whereas penetration depth, depth-to-width ratio, heat input and width of the heat-affected zone were considered as output variables for the investigations. Using the experimental data, statistical models were generated for the response characteristics. Four different case studies, simulating the real-time fabrication problem, were considered and the optimization was carried out using HTS. Validation tests were also carried out for these case studies and 3D surface plots were generated to confirm the effectiveness of the HTS algorithm. It was found that the HTS algorithm effectively optimized the process parameters and negligible errors were observed when predicted and experimental values compared. HTS algorithm is a parameter-less optimization technique and hence it is easy to implement with higher effectiveness.


2016 ◽  
Vol 880 ◽  
pp. 21-24
Author(s):  
Kamlesh Kumar ◽  
Pankaj Ahirwar ◽  
Manoj Masanta

In this study, AISI 1020 plate of 6 mm thickness has been welded by autogenous TIG welding process maintaining different root gap (0, 0.5, 0.75 and 1 mm). The weld bead profile and the tensile strength of the welded joint has been analysed. From the experimental results it is revealed that, for increasing the root gap, weld depth penetration increases; whereas weld bead width and heat affected zone (HAZ) is almost uniform. However, at the similar condition, under-filling of the weld joint increases with the increase in root gap. For using 1 mm root gap, weld joint exhibit full depth of penetration and maximum tensile strength, along with higher under-filling.


Sign in / Sign up

Export Citation Format

Share Document