scholarly journals Comparative Study on Welding Characteristics of Laser-CMT and Plasma-CMT Hybrid Welded AA6082-T6 Aluminum Alloy Butt Joints

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3300 ◽  
Author(s):  
Zhibin Xin ◽  
Zhibin Yang ◽  
Han Zhao ◽  
Yuxin Chen
Keyword(s):  
Aluminum Alloy ◽  
Comparative Study ◽  
Welded Joints ◽  
High Speed ◽  
Shear Fracture ◽  
Welding Process ◽  
Hybrid Welding ◽  
Micro Hardness ◽  
Butt Joints ◽  
Promising Alternative

Laser-CMT (Cold Metal Transfer) and plasma-CMT hybrid welding are two promising alternative joining technologies for traditional Metal-Inert-Gas (MIG) welding of the aluminum alloy joints in the high speed trains manufacturing industry. In this work, a comparative study on the weld formation, microstructure, micro-hardness, and mechanical properties of the butt joints in the two welding methods was conducted. The results indicate that the overall quality of the laser-CMT and plasma-CMT welds were good, especially of the laser-CMT hybrid weld, and the laser-CMT hybrid welding process needed a lower heat input. The width of the partially melted zone of the laser-CMT hybrid weld was narrower than that in the plasma-CMT hybrid weld. Micro-hardness test results show that two distinct softening regions were identified in the heat affected zone, and the micro-hardness values of each zone in the laser-CMT hybrid weld were lower than that in the plasma-CMT hybrid weld. The tensile strength of the laser-CMT hybrid welded joints was higher than that of the plasma-CMT hybrid welded joints, which could reach up to 79.4% and 73.7% of the base materials, respectively. All the fractures occurred in the softening region and exhibited a ductile shear fracture with a shear angle of approximately 45°. The fractographs manifested that the laser-CMT and plasma-CMT hybrid welded joints presented ductile fracture and ductile-brittle fracture features, respectively.

Elements loss analysis based on spectral diagnosis in laser-arc hybrid welding of aluminum alloy

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744036
Author(s):  
Yong Chen ◽  
Hui Chen ◽  
Minhao Zhu ◽  
Tao Yang ◽  
Lin Shen
Keyword(s):  
Aluminum Alloy ◽  
High Speed ◽  
Welding Process ◽  
Spectral Intensity ◽  
Hybrid Welding ◽  
Loss Analysis ◽  
Welding Defects ◽  
High Speed Trains ◽  
Arc Current ◽  
Weld Area

Aluminum alloy has been widely used in automobiles, high-speed trains, aerospace and many other fields. The loss of elements during welding process causes welding defects and affects the microstructure and properties of the joints. This paper discusses the correlation between welding process, spectral intensity and loss of elements in laser-arc hybrid welding of Al alloys. The results show that laser power and arc current have a significant impact on the spectral intensity and loss of elements. Compared with the base metal, the contents of alloying elements in the weld area are lower. The burning losses of alloy elements increase with the welding heat input.

scholarly journals Effect of Droplet Transition on the Dynamic Behavior of the Keyhole during 6061 Aluminum Alloy Laser-MIG Hybrid Welding

2021 ◽  
Author(s):  
Yue Li ◽  
Yanqiu Zhao ◽  
Xudong Zhou ◽  
Xiaohong Zhan
Keyword(s):  
Aluminum Alloy ◽  
Dynamic Behavior ◽  
Molten Pool ◽  
High Speed ◽  
Welding Process ◽  
Welding Parameters ◽  
Hybrid Welding ◽  
Camera System ◽  
6061 Aluminum Alloy ◽  
Droplet Transition

Abstract The simulation method in laser-MIG hybrid welding, which involves two heat sources and multiple welding parameters, is beneficial to reveal the complex physical phenomena and dynamic behavior of molten pool keyhole during welding process. In this investigation, laser-MIG hybrid welding for 6-mm-thick 6061 aluminum alloy was performed under different heat input by the high-power disc laser, MIG welding system and KUKA Robot. The high-speed camera system was used to observe the droplet transition phenomenon in the welding process. Besides, a thermal-fluid coupling model was established to simulate the temperature field and flow field, which were changed by the droplet transfer during laser-MIG hybrid welding. The experimental and simulated results showed that the droplet transition behavior affected the formation of the keyhole. The keyhole was the smallest when the droplet contacted the molten pool. In addition, the droplet transition brought external momentum and energy to the molten pool, which was conducive to the increase of the flow rate of the molten pool.

Laser-Arc Hybrid Welding Process and Joint Performances of 6106-T6 Aluminum Alloy Profiles for High Speed Trains

2019 ◽  
Vol 46 (12) ◽  
pp. 1202004
Author(s):  
韩晓辉 Han Xiaohui ◽  
李帅贞 Li Shuaizhen ◽  
毛镇东 Mao Zhendong ◽  
温鹏 Wen Peng ◽  
栗忠秀 Li Zhongxiu ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
High Speed ◽  
Welding Process ◽  
Hybrid Welding ◽  
High Speed Trains

scholarly journals Increasing of the Mechanical Properties of Friction Stir Welded Joints of 6061 Aluminum Alloy by Introducing Alumina Particles

2017 ◽  
Vol 17 (2) ◽  
pp. 29-40 ◽  
Author(s):  
M. A. Tashkandi ◽  
J. A. Al-Jarrah ◽  
M. Ibrahim
Keyword(s):  
Aluminum Alloy ◽  
Base Metal ◽  
Welded Joints ◽  
Volume Fraction ◽  
Welding Process ◽  
Welding Zone ◽  
6061 Aluminum Alloy ◽  
Friction Stir ◽  
Alumina Particles ◽  
Welding Line

AbstractThe main aim of this investigation is to produce a welding joint of higher strength than that of base metals. Composite welded joints were produced by friction stir welding process. 6061 aluminum alloy was used as a base metal and alumina particles added to welding zone to form metal matrix composites. The volume fraction of alumina particles incorporated in this study were 2, 4, 6, 8 and 10 vol% were added on both sides of welding line. Also, the alumina particles were pre-mixed with magnesium particles prior being added to the welding zone. Magnesium particles were used to enhance the bonding between the alumina particles and the matrix of 6061 aluminum alloy. Friction stir welded joints containing alumina particles were successfully obtained and it was observed that the strength of these joints was better than that of base metal. Experimental results showed that incorporating volume fraction of alumina particles up to 6 vol% into the welding zone led to higher strength of the composite welded joints as compared to plain welded joints.

Simulation on Temperature and Residual Stress Field of Laser-MIG Hybrid Welding of A6N01-T5 Alloy

2011 ◽  
Vol 399-401 ◽  
pp. 2040-2043 ◽  
Author(s):  
Da Li ◽  
Hua Ji ◽  
Yan Liu ◽  
Guo Qing Gou ◽  
Hui Chen ◽  
...  
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Stress Field ◽  
Welded Joints ◽  
Hybrid Welding ◽  
Mig Welding ◽  
Residual Stress Field ◽  
Heat Cycling

MIG welding and laser-MIG hybrid welding have been widely used to joint aluminum alloy in recent years. Residual stress and heat cycling of MIG welding and laser-MIG hybrid welding are analyzed by SYSWELD software. The results show that the peak values of the stress in hybrid welding is 30~50% less than the results in the MIG welded joints.

scholarly journals Assessment of the Effect of Laser Welding on the Properties and Structure of TMCP Steel Butt Joints

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1312 ◽  
Author(s):  
Jacek Górka
Keyword(s):  
Laser Beam ◽  
Welded Joints ◽  
Research Work ◽  
Laser Beam Welding ◽  
Welding Process ◽  
Tensile Tests ◽  
Carbon Equivalent ◽  
Quality Level ◽  
Butt Joints ◽  
Plastic Properties

The research work and related tests aimed to identify the effect of filler metal-free laser beam welding on the structure and properties of butt joints made of steel 700MC subjected to the TMCP (thermo-mechanically controlled processed) process. The tests involved 10-mm thick welded joints and a welding linear energy of 4 kJ/mm and 5 kJ/mm. The inert gas shielded welding process was performed in the flat position (PA) and horizontal position (PC). Non-destructive testing enabled classification of the tested welded joints as representing the quality level B in accordance with the requirements set out in standard 13919-1. Destructive tests revealed that the tensile strength of the joints was 5% lower than S700MC steel. The results of tensile tests and changes in structure were referred to joints made using the MAG (Metal Active Gas) method. The tests of thin films performed using a high-resolution scanning transmission electron microscope revealed that, during laser beam welding, an increase in dilution was accompanied by an increase in the content of alloying microadditions titanium and niobium, particularly in the fusion area. A significant content of hardening phases in the welded joint during cooling led to significant precipitation hardening by fine-dispersive (Ti,Nb)(C,N) type precipitates being of several nanometres in size, which, in turn, resulted in the reduction of plastic properties. An increase in the concentration of elements responsible for steel hardening, i.e., Ti and Nb, also contributed to reducing the weld toughness below the acceptable value, which amounts to 25 J/cm2. In cases of S700MC, the analysis of the phase transformation of austenite exposed to welding thermal cycles and the value of carbon equivalent cannot be the only factors taken into consideration when assessing weldability.

scholarly journals Metallurgical and Mechanical Characterization of High-Speed Friction Stir Welded AA 6082-T6 Aluminum Alloy

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4211 ◽  
Author(s):  
Anton Naumov ◽  
Iuliia Morozova ◽  
Evgenii Rylkov ◽  
Aleksei Obrosov ◽  
Fedor Isupov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Welding Speed ◽  
Welded Joints ◽  
High Speed ◽  
Structural Characteristics ◽  
Tensile Fracture ◽  
Friction Stir ◽  
Microhardness Distribution ◽  
Aluminum Sheets

The objective of this study was to investigate the effect of the high welding speed on the mechanical properties and their relations to microstructural characteristics of butt friction stir welded joints with the use of 6082-T6 aluminum alloy. The aluminum sheets of 2.0 mm thick were friction stir welded at low (conventional FSW) and high welding speeds (HSFSW) of 200 and 2500 mm/min, respectively. The grain size in the nugget zone (NZ) was decreased; the width of the softened region was narrowed down as well as the lowest microhardness value located in the heat-affected zone (HAZ) was enhanced by HSFSW. The increasing welding speed resulted in the higher ultimate tensile strength and lower elongation, but it had a slight influence on the yield strength. The differences in mechanical properties were explained by analysis of microstructural changes and tensile fracture surfaces of the welded joints, supported by the results of the numerical simulation of the temperature distribution and material flow. The fracture of the conventional FSW joint occurred in the HAZ, the weakest weld region, while all HSFSW joints raptured in the NZ. This demonstrated that both structural characteristics and microhardness distribution influenced the actual fracture locations.

Austenite Decomposition Kinetics in Laser-Hybrid Welding of Steel of Strength Class K52

2019 ◽  
Vol 946 ◽  
pp. 950-955 ◽  
Author(s):  
A.I. Romantsov ◽  
M.A. Fedorov ◽  
D.G. Lodkov
Keyword(s):  
Welded Joints ◽  
Strength Class ◽  
Defect Formation ◽  
Welding Process ◽  
Decomposition Kinetics ◽  
Hybrid Welding ◽  
Austenite Decomposition ◽  
Laser Hybrid Welding ◽  
Laser Hybrid ◽  
The Impact

A modern technology for joining materials welding is commonly used in various industries. It is a process of interaction of thermal, mechanical and metallurgical properties and behaviors. Complex phenomena, such as solidification, microstructural changes and defect formation, have a great impact on the quality of welded joints. This article presents the results of studying the features of the austenite decomposition kinetics in the application of laser-hybrid welding technology, in a combination with multi-arc automatic submerged arc welding. The cooling rates are determined, affecting the change in properties of HAZ of welded joints on pipe steel of strength class K52. Using the dilatometric method, studies were conducted and thermo-kinetic and structural diagrams were constructed. Analysis of diagrams and microstructures showed that, as a result of the impact of the laser-hybrid welding process in the area of HAZ, the decomposition of austenite occurs mainly in the martensitic zone, followed by the formation of a bainite-perlite structure, due to recrystallization from the heat generated by the facing seams.

scholarly journals Experimental and numerical analysis of incremental magnetic pulse welding of dissimilar sheet metals

2019 ◽  
Vol 6 ◽  
pp. 7
Author(s):  
Verena Psyk ◽  
Maik Linnemann ◽  
Christian Scheffler
Keyword(s):  
High Speed ◽  
Welding Process ◽  
Deep Understanding ◽  
Magnetic Pulse ◽  
Pulsed Magnetic Fields ◽  
Promising Alternative ◽  
Magnetic Pulse Welding ◽  
Pulse Welding ◽  
The Individual ◽  
Weld Seams

Magnetic pulse welding is a solid-state welding process using pulsed magnetic fields resulting from a sudden discharge of a capacitor battery through a tool coil in order to cause a high-speed collision of two metallic components, thus producing an impact-welded joint. The joint is formed at room temperature. Consequently, temperature-induced problems are avoided and this technology enables the use of material combinations, which are usually considered to be non-weldable. The extension of the typically linear weld seam can reach several hundred millimetres in length, but only a few millimetres in width. Incremental or sequential magnetic pulse welding is a promising alternative to obtain larger connected areas. Here, the inductor is moved relative to the joining partners after the weld sequence and then another welding process is initiated. Thus, the welded area is extended by arranging multiple adjacent weld seams. This article demonstrates the feasibility of incremental magnetic pulse welding. Furthermore, the influence of important process parameters on the component quality is investigated and evaluated. The suitability of different mechanical testing methods for determining the strength of the individual weld seams is discussed. The results of numerical simulation are consulted in order to obtain deep understanding of the observed effects.

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