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.

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 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.

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.

scholarly journals Microstructure, Mechanical Properties and Corrosion Behavior of the Aluminum Alloy Components Repaired by Cold Spray with Al-Based Powders

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1633
Author(s):  
Zhiyi Zhang ◽  
Xiaoguang Sun ◽  
Shiming Huang ◽  
Xiaohui Han ◽  
Ping Zhu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Cold Spray ◽  
Corrosion Behavior ◽  
High Speed ◽  
Neutral Salt ◽  
Cold Spray Process ◽  
Spray Process ◽  
High Speed Trains ◽  
Mechanical Properties And Corrosion

Aluminum alloy components of high-speed trains have a great risk of being corroded by various corrosive medium due to extremely complex atmospheric environments. This will bring out huge losses and reduce the safety and stability of trains. In order to solve the problem, cold spray process was used for repairing the damage of the aluminum alloy components with Al-based powders. Microstructure, mechanical properties and corrosion behavior were studied. The results indicated that there were very few pores and cracks in the repaired areas after repairing. The average microhardness of the repaired areas was 54.5 HV ± 3.4 HV, and the tensile strength of the repaired samples was 160.4 MPa. After neutral salt spray tests for 1000 h, the rate of mass loss of the samples repaired by cold spray was lower than that of 6A01 aluminum alloy. The electrochemical test results showed that the repaired areas had a higher open circuit potential than 6A01 aluminum alloy. As a result, the repaired areas such as the anode protected its nearby substrate. The samples repaired by cold spray exhibited better corrosion than 6A01 aluminum alloy. Cold spray process and Al-based powders are applicable for repairing the aluminum alloy components of high-speed trains.

Capacitor Discharge Weld Modelling Using Ultra High Speed Photography

1993 ◽  
Vol 314 ◽  
Author(s):  
R. D. Wilson ◽  
J. A. Hawk ◽  
J. H. Devletian
Keyword(s):  
High Speed ◽  
Welding Process ◽  
Travel Speed ◽  
Analytical Models ◽  
High Speed Photography ◽  
Welding Time ◽  
Capacitor Discharge ◽  
Ultra High Speed ◽  
High Cooling Rates ◽  
Weld Area

AbstractCapacitor discharge welding (CDW) is a rapid solidification joining process where high cooling rates (106 K/s) are obtained as a result of the large weld surface area to small weld volume. The objective of this study, directed by the U.S. Bureau of Mines and the Oregon Graduate Institute of Science and Technology, was to use ultra-high speed photography to quantify transient arc behavior during the CDW cycle. The simple cylindrical geometries of the CD welds have been used to formulate analytical models which are compared to the high speed photographs of the welding process. The high speed photographs were analyzed with respect to welding time and process weld variables and compared to predicted values from the analytical model. The detailed photographic analyses revealed that material is continuously ejected as a plasma from the weld area due to induced magnetic forces, rather than having the liquid metal squeezed out of the weld upon contact. It was found that welding time was controlled by tip length and drop height. Results from high speed photographs found the arc travel speed around tube welds to be 109m/s. Finally, the high speed photographs revealed that the velocity of arc propagation during ignition was fast enough to allow the CDW process to be modelled as onedimensional heat flow.

scholarly journals Characteristics of Welding and Arc Pressure in the Plasma–TIG Hybrid Welding Process

2018 ◽  
Author(s):  
Bo Wang ◽  
Xunming Zhu ◽  
Hongchang Zhang ◽  
Hongtao Zhang ◽  
Jicai Feng
Keyword(s):  
Arc Welding ◽  
Gas Flow ◽  
Welding Process ◽  
Hybrid Welding ◽  
Plasma Arc ◽  
Arc Pressure ◽  
Arc Current ◽  
Arc Welding Process ◽  
Welding Processes

In this article, a novel hybrid welding process called plasma-TIG coupled arc welding was proposed to improve the efficiency and quality of welding by utilizing the full advantage of plasma and TIG welding processes. The two arcs of plasma and TIG were pulled into each other into one coupled arc under the effect of Lorentz force and plasma flow force during welding experiments. The arc behavior of coupled arc was studied by means of it’s arc profile, arc pressure and arc force conditions. The coupled arc pressure distribution measurements were performed. The effects of welding conditions on coupled arc pressure were evaluated and the maximum coupled arc pressure was improved compared with single-plasma arc and single-TIG arc. It was found that the maximum arc pressure was mainly determined by plasma arc current and plasma gas flow. According to the results, the proposed coupled arc welding process have both advantages of plasma arc and TIG method, and it has a broad application prospect.

Investigation of porosity in rotating laser-MIG hybrid welding A6N01 aluminum alloy

2019 ◽  
Vol 33 (01n03) ◽  
pp. 1940029
Author(s):  
Yanjie Yin ◽  
Hui Chen ◽  
Xiaoyi Yang ◽  
Shuang He
Keyword(s):  
Aluminum Alloy ◽  
Molten Pool ◽  
High Speed ◽  
Rotation Frequency ◽  
Good Prospect ◽  
Hybrid Welding ◽  
Weld Penetration ◽  
X Ray ◽  
Conventional Laser ◽  
Alloy Weld

In this study, rotating laser was employed to reduce the porosity defect in laser-MIG hybrid welding A6N01 aluminum alloy. The influence of laser rotating frequency and rotating radius on the weld were researched respectively. The images of the molten pool were acquired by the high-speed camera, and X-ray images of the weld were calculated by binarization. The result shows that rotating laser-MIG hybrid welding has a dramatic effect on suppressing the generation of porosity, which indicates the possibility to obtain the A6N01 aluminum alloy weld with few pores. With proper parameters about rotation frequency (50 Hz) and rotation radius (2 mm), the porosity decreased obviously from 8.41% to 5.68%, and there was hardly distinct change in the weld penetration. The keyhole stability of rotating laser-MIG hybrid welding was improved, compared with the conventional laser-MIG hybrid welding. On account of laser beam stirring the metal molten pool, it was beneficial for the pores to escape from the molten pool. The rotating laser-MIG hybrid welding shows a good prospect.

scholarly journals Harmonic Loss Analysis of the Traction Transformer of High-Speed Trains Considering Pantograph-OCS Electrical Contact Properties

Energies ◽  
2013 ◽  
Vol 6 (11) ◽  
pp. 5826-5846 ◽  
Author(s):  
Jin Wang ◽  
Zhongping Yang ◽  
Fei Lin ◽  
Junci Cao
Keyword(s):  
High Speed ◽  
Electrical Contact ◽  
Loss Analysis ◽  
High Speed Trains

Study on the AZ31B Magnesium Alloy in the Application on High-Speed Trains

2012 ◽  
Vol 535-537 ◽  
pp. 875-879 ◽  
Author(s):  
Jia Zhen Liu ◽  
Yan Hui Zhao ◽  
Lei Song ◽  
Zhong Xia Xiang
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Magnesium Alloy ◽  
High Speed ◽  
Equivalent Stress ◽  
Strength Analysis ◽  
Az31b Magnesium Alloy ◽  
High Speed Trains ◽  
6063 Aluminum Alloy ◽  
The Impact

6063 aluminum alloys are used as the luggage rack’s material on high-speed trains recently. The study on the AZ31B magnesium alloy is aimed to demonstrate the feasibility of the magnesium alloy’s application as the material of the luggage rack on high-speed trains. First, the mechanical properties of the AZ31B magnesium was obtained after a series of experimental tests on basic mechanical properties of the AZ31B magnesium alloy. The results show that the strength of the magnesium alloy is 1.25 times of the 6063 aluminum alloy and the impact toughness of the AZ31B magnesium alloy is twice as much as the 6063 aluminum alloy. Second, the stress distribution and the maximum value of the equivalent stress in given loading conditions was obtained by finite element strength analysis on the structure of the aluminum alloy luggage rack on high-speed trains. And the FE analysis results indicate that if the AZ31B magnesium alloy is used as the material of the luggage rack instead of the 6063 aluminum alloy, it will have a weight loss of the luggage rack for approximately 33%. In addition, the application of AZ31B magnesium alloy has more advantages in energy-saving, environmental protection and safety control.

Running Safety Assessment of Trains on Bridges under Earthquakes Based on Spectral Intensity Theory

2021 ◽  
Author(s):  
Wei Guo ◽  
Yang Wang ◽  
Hanyun Liu ◽  
Yan Long ◽  
Lizhong Jiang ◽  
...  
Keyword(s):  
High Speed ◽  
Safety Assessment ◽  
Low Frequency ◽  
Interaction Model ◽  
Spectral Intensity ◽  
Dynamic Responses ◽  
Running Safety ◽  
High Speed Trains ◽  
Track Bridge ◽  
Multi Body

The main goal of this paper is to perform the safety assessment of high-speed trains (HSTs) on the simply supported bridges (SSBs) under low-level earthquakes, which are frequently encountered by HSTs, utilizing spectral intensity (SI) index. First, the HST’s limit displacements, which are calculated by using the multi-body train model with detailed wheel–rail relationship, varying with train speed, frequency and amplitude of a sinusoidal base excitation are obtained. Then, based on the obtained HST’s limit displacements, the spectral intensity limits (SIL) graded by the train’s running speed are calculated, and the relationship between the bridge seismic dynamic responses and the train’s running safety was established. Next, the method that utilizes the SI and the SIL indexes to evaluate the HST’s running safety was proposed and verified by comparing with the evaluation result of the train–track–bridge interaction model. Based on the proposed SI index, the HST’s running safety on the SSBs was evaluated under earthquakes, considering different pier heights and site types. The results showed that the low-frequency components of the ground motions are unfavorable to the HST’s running safety, and the height of bridge piers has a significant impact on running safety.

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