scholarly journals A Unified Adjustment Model for Gaussian Pulse Welding on Aluminum Alloys

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 671
Author(s):  
Qiang Zhu ◽  
Ping Yao ◽  
Xiaoyan Yu ◽  
Bin Xie ◽  
Jiaxiang Xue ◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
Weld Zone ◽  
Base Material ◽  
Welding Process ◽  
Welding Current ◽  
Gaussian Pulse ◽  
Metallographic Analysis ◽  
Fish Scale ◽  
Adjustment Model ◽  
Pulse Welding

To solve the challenge of welding aluminum alloys, a unified adjustment model for Gaussian pulse welding is established. This model can achieve improved welding performance by adjusting the base current of the weak pulse group within a specific range of average welding current inputs. The flat overlaying welding is carried out on the base material: 6061 aluminum alloys with thicknesses of 2 mm, 3 mm, and 5 mm. A stable welding process, indicated by reduced spatter, is produced, with a soft arc sound and good repeatability in the waveforms of the real-time current and voltage. The weld has a shiny surface and regular fish scale ripples. Metallographic analysis shows that the fusion line is clear, and there are no visible defects, while the weld zone has fine dendritic structures. The tensile test results indicate that fractures occur in the heat-affected zone, and that the tensile strength reaches about 68% of that of the base metal.

FSW of Aluminum Alloys: Effect of Operating Parameters on the Weld Quality

2015 ◽  
Vol 640 ◽  
pp. 43-50 ◽  
Author(s):  
S. El Mouhri ◽  
S. Ettaqi ◽  
A. Laazizi ◽  
Stephane Benayoun
Keyword(s):  
Process Parameters ◽  
Weld Zone ◽  
Base Material ◽  
Welding Process ◽  
Industrial Applications ◽  
Metallic Alloys ◽  
Metallographic Analysis ◽  
Operating Parameters ◽  
Weld Quality ◽  
Friction Stir

The Friction Stir Welding FSW is a welding process in the solid state to join metallic alloys that is used in many industrial applications such as aerospace, automotive and shipbuilding. The process parameters such as the geometry of the tool, the speed of rotation and the speed of advance play a major role in determining the weld quality. In this work, an attempt was made to establish a relationship between the properties of the base material and FSW process parameters. Welds were made using AA1050 Aluminum alloy with different combination of parameters. Metallographic analysis was performed to verify the (faulty or fault-free) weld quality. Tests microhardness, tensile and bending were carried out to study the changes in the mechanical properties in the weld zone.

scholarly journals A Study on Vertical Upward Welding of Dissimilar Material and Thickness of Thin Plates Using Novel TIG Welding Process

2019 ◽  
Author(s):  
Ngo Huu Manh ◽  
Nguyen Van Anh ◽  
Murata Akihisa ◽  
Hideno Terasaki
Keyword(s):  
Base Metal ◽  
Heat Input ◽  
Weld Zone ◽  
Welding Process ◽  
Welding Current ◽  
Tig Welding ◽  
Dissimilar Material ◽  
Thin Plates ◽  
Welding Defects ◽  
Welding Position

A study about influence of heat input on welding defects in vertical upward welding position for dissimilar material and thickness using a new variation of TIG welding torch is done with support of advanced inspection methods SEM and EBSD. With vertical upward welding position, control heat input plays an important role to keep the weld stabilization without defects. On the other hand, TIG welding process using a conventional TIG torch (conventional TIG welding process) has low efficiency and it is difficult to control heat input with high accuracy. So, it is considered that using conventional TIG torch is still a challenge for welding thin plates. In this case, a new variation of TIG torch has been developed. This torch used a constricted nozzle to improve plasma arc characteristics. As a result, it can control efficiently the heat input to prevent the excessive or insufficiency for joining thin sheets. For evaluation of welding quality, advanced examination methods SEM and EBSD were applied to directly observe the welding defects. From the results, the formation mechanism of blowhole inside weld zone in case of welding dissimilar material and thickness was discussed. It is pointed out that when sufficient welding current, the change from weld zone to base metal is uniform, no welding defects such as blowhole was seen. However, in case of low welding current, the thinner base metal is insufficient fusion and the change between weld zone and base metal is not uniform. The blowhole was observed at SS400 material side.

scholarly journals EFFECT OF WELDING PROCESS PARAMETERS ON TENSILE OF LOW CARBON STEEL 283 G.C

2022 ◽  
Vol 26 (1) ◽  
pp. 79-86
Author(s):  
Hussain Hayyal ◽  
◽  
Nadhim M. Faleh ◽  
Keyword(s):  
Carbon Steel ◽  
Tensile Stress ◽  
Welded Joints ◽  
Arc Welding ◽  
Low Carbon Steel ◽  
Base Material ◽  
Welding Process ◽  
Welding Current ◽  
Low Carbon ◽  
Tungsten Electrode

In this study, three welding methods are used. The purpose to investigation the effects of SMAW, SAW, and gas tungsten arc welding (GTAW) on the tensile stress of low carbon steel conforming to ASTM 283 c. 8mm thick plates are used as base material for butt welded joints. The tensile properties of the welded joints were evaluated and the results were compared by experts using the Taguchi method to design three levels of each parameter (current, voltage and displacement speed). From this research, it is found that compared to metal shielded arc welding and submerged arc welding, the pulling effect of the gas shielded welding joint of the tungsten electrode is the best. This is mainly due to the presence of The results of using analysis of variance (ANOVA) to estimate important parameters show that welding current and speed of the weld have a significant effect on tensile stress .the experimental results are in agreement with predicted results, and the maximum error is 3%..

Properties of Friction-Stir Welded Aluminum Alloys 6111 and 5083

2008 ◽  
Vol 130 (3) ◽  
Author(s):  
W. Gan ◽  
K. Okamoto ◽  
S. Hirano ◽  
K. Chung ◽  
C. Kim ◽  
...  
Keyword(s):  
Aluminum Alloys ◽  
Weld Zone ◽  
Base Material ◽  
Natural Aging ◽  
Tensile Tests ◽  
Travel Speed ◽  
Minimum Phase ◽  
Friction Stir ◽  
Base Materials ◽  
Fsw Parameters

Friction-stir welding (FSW) promises joints with low porosity, fine microstructures, minimum phase transformation, and low oxidation compared with conventional welding techniques. It is capable of joining combinations of alloys not amenable to conventional welding. Certain combinations of FSW parameters were used to create FSWs of aluminum alloys 5083-H18 and 6111-T4, and the physical weld defects were measured. The mechanical behavior of FSW welds made under the most favorable choice of parameters was determined using tensile tests and hardness measurements and was correlated to the microstructures of the weld and base material. Stir zones (SZs) in the 5083 specimens were much softer than the strain-hardened base materials. SZs in the 6111 material are approximately as hard as the base material. Natural aging of 6111 FSW specimens occurred in some parts of the heat-affected zone and produced hardening for up to 12weeks after welding. Annealing of 5083 FSW specimens produced abnormal grain growth (AGG) for welds produced under certain welding conditions and in certain parts of the weld zone. AGG is more severe for low-heat conditions, i.e., higher tool travel speed but lower rotational speed. The conditions for most favorable FSW are presented, as well as the expected microstructures and mechanical properties, along with the weld conditions that promote AGG.

Microstructure and Mechanical Properties of GMAW Welded Joints Er-Containing Aluminum Alloy

2020 ◽  
Vol 993 ◽  
pp. 92-99
Author(s):  
Hao Zhen Guo ◽  
Li Cui ◽  
Hui Huang ◽  
Xiao Guo ◽  
Ding Yong He
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Penetration Depth ◽  
Welded Joint ◽  
Weld Zone ◽  
Welding Process ◽  
Welding Current ◽  
Depth Range ◽  
Arc Voltage ◽  
Microstructure And Mechanical Properties

This present work explored the welding process of gas metal arc welding for 4mm 5E61 Er-containing aluminum alloy, and then analyzed the microstructure and mechanical properties of the welded joint. The results demonstrated that when the welding current was 160A-220A, the welded joint penetration depth range was 5.75mm to 6.72mm, the melting width ranging from 9.68mm to 11.61mm. When the arc voltage increased from 17.5V to 22.5V, the penetration depth of the welded joint reduced from 6.95mm to 5.57mm, and the melting width ranged from 6.64mm to 11.86mm. When the welding current was 170A, the arc voltage was 17.5V, and the welding speed was 10mm/s. In the third case, a fully penetrated welded joint can be obtained and the joint strength was the highest value. The yield strength reached 192 MPa, the tensile strength can be 301 MPa, and the fracture location occurred in the HAZ. The weld zone of the welded joint mainly consist of the equiaxed dendrites size of 50 μm. The micro-hardness of the weld zone was lower than that of the base metal, and there was no obvious softening phenomenon in the heat affected zone.

scholarly journals Double-Pulse Triple-Wire MIG Welding of 6082-T6 Aluminum Alloy: Process Characteristics and Joint Performances

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1388
Author(s):  
Ke Yang ◽  
Fei Wang ◽  
Hongbing Liu ◽  
Peng Wang ◽  
Chuanguang Luo ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Aluminum Alloy ◽  
High Efficiency ◽  
Welding Process ◽  
Pulse Frequency ◽  
Double Pulse ◽  
Fish Scale ◽  
Mig Welding ◽  
Process Characteristics ◽  
Pulse Welding

High-efficiency and high-quality welding has always been the focus of welding research. This article proposes a novel double-pulse, triple-wire MIG welding process for the welding of 6082-T6 aluminum alloy. The process characteristics of welding arc and droplet transfer were studied, and the performances of weld formation, morphology, hardness, and tensile strength were tested for the 1 Hz, 3 Hz, and 5 Hz double-pulse welding and normal-pulse welding. It was found that in the welding process, the pulsed arc steadily alternated among three welding wires without arc interruption, and the arc length changed periodically with the double-pulse frequency. The droplets transferred with a stable one-pulse-one-drop mode. Besides, a proper double-pulse frequency, e.g., 3 Hz in this case, was conducive to forming good welds with regular fish-scale patterns and no pores. The tensile strength of the joint could reach 64% of the base material’s tensile strength, and its fracture belonged to plastic fracture, which occurred in the HAZ. This new welding method will have great potential in aluminum alloy welding.

scholarly journals Metallurgical Characterization of Welded Joint of Nanostructured Bainite: Regeneration Technique versus Post Welding Heat Treatment

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4841
Author(s):  
Aleksandra Królicka ◽  
Krzysztof Radwański ◽  
Aleksandra Janik ◽  
Paweł Kustroń ◽  
Andrzej Ambroziak
Keyword(s):  
Heat Treatment ◽  
Welded Joint ◽  
Construction Material ◽  
Weld Zone ◽  
Base Material ◽  
Welding Process ◽  
Solidification Structure ◽  
Hardness Distribution ◽  
Diffusion Type

One of the main limitations in application of nanostructured carbide-free bainite as a construction material is the difficulty of joining. This research presents a structural characterization of welded joints of medium carbon 55Si7 grade steel after the welding process with a regeneration technique as well as post welding heat treatment (PWHT). The hardness distribution of the welded joint with regeneration exhibit an overall decrease in hardness when compared to the base material and a significant decrease in hardness was observed in the heat-affected zone (HAZ). Unfavorable hardness distribution was caused by the presence of diffusion-type transformations products (pearlite) in the HAZ and bainite degradation processes. On the other hand, welding with the PWHT promotes the achievement of a comparable level of hardness and structure as in the base material. However, a slight decrease in hardness was observed in the weld zone due to the micro-segregation of the chemical composition caused by the indissoluble solidification structure. Based on the structural analysis, it was found that steel with relatively low hardenability (55Si7) should be welded using PWHT rather than a regeneration technique.

Effects of bottom plate in friction stir welding of AA6061-T6

2020 ◽  
Vol 118 (1) ◽  
pp. 108
Author(s):  
M.A. Vinayagamoorthi ◽  
M. Prince ◽  
S. Balasubramanian
Keyword(s):  
Mechanical Properties ◽  
Axial Load ◽  
Weld Zone ◽  
Welding Process ◽  
Bottom Plate ◽  
Welding Parameters ◽  
Nugget Zone ◽  
Friction Stir ◽  
Weld Joints ◽  
Fine Grain

The effects of 40 mm width bottom plates on the microstructural modifications and the mechanical properties of a 6 mm thick FSW AA6061-T6 joint have been investigated. The bottom plates are placed partially at the weld zone to absorb and dissipate heat during the welding process. An axial load of 5 to 7 kN, a rotational speed of 500 rpm, and a welding speed of 50 mm/min are employed as welding parameters. The size of the nugget zone (NZ) and heat-affected zone (HAZ) in the weld joints obtained from AISI 1040 steel bottom plate is more significant than that of weld joints obtained using copper bottom plate due to lower thermal conductivity of steel. Also, the weld joints obtained using copper bottom plate have fine grain microstructure due to the dynamic recrystallization. The friction stir welded joints obtained with copper bottom plate have exhibited higher ductility of 8.9% and higher tensile strength of 172 MPa as compared to the joints obtained using a steel bottom plate.

scholarly journals Experimental Study on Laser-MIG Hybrid Welding of Thick High-Mn Steel Plate for Cryogenic Tank Production

2021 ◽  
Vol 9 (6) ◽  
pp. 604
Author(s):  
Du-Song Kim ◽  
Hee-Keun Lee ◽  
Woo-Jae Seong ◽  
Kwang-Hyeon Lee ◽  
Hee-Seon Bang
Keyword(s):  
Low Temperature ◽  
Yield Strength ◽  
Steel Plate ◽  
Weld Zone ◽  
Base Material ◽  
Hardness Test ◽  
Steel Plates ◽  
Hybrid Welding ◽  
Temperature Impact ◽  
Mn Steel

The International Maritime Organization has recently updated the ship emission standards to reduce atmospheric contamination. One technique for reducing emissions involves using liquefied natural gas (LNG). The tanks used for the transport and storage of LNG must have very low thermal expansion and high cryogenic toughness. For excellent cryogenic properties, high-Mn steel with a complete austenitic structure is used to design these tanks. We aim to determine the optimum welding conditions for performing Laser-MIG (Metal Inert Gas) hybrid welding through the MIG leading and laser following processes. A welding speed of 100 cm/min was used for welding a 15 mm thick high-Mn steel plate. The welding performance was evaluated through mechanical property tests (tensile and yield strength, low-temperature impact, hardness) of the welded joints after performing the experiment. As a result, it was confirmed that the tensile strength was slightly less than 818.4 MPa, and the yield strength was 30% higher than base material. The low-temperature impact values were equal to or greater than 58 J at all locations in the weld zone. The hardness test confirmed that the hardness did not exceed 292 HV. The results of this study indicate that it is possible to use laser-MIG hybrid welding on thick high-Mn steel plates.

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