scholarly journals Experimental investigation of the weldability of tubular dissimilar materials using the electromagnetic welding process

2017 ◽  
Vol 8 (1) ◽  
pp. 8 ◽  
Author(s):  
Lodewijk Roeygens ◽  
Wim De Waele ◽  
Koen Faes

This paper describes the magnetic pulse welding process (MPW) for tubes. Material combinations of aluminium to steel and copper to aluminium were experimentally evaluated. The first major goal of this work is to experimentally obtain the optimal input parameters like the discharge energy, the stand-off distance and the tool overlap for MPW of the material combinations. Welding windows with all possible input parameters are created for both material combinations. Furthermore, a comparison is done between three coil systems; a single turn coil with field shaper, a single turn coil with a field shaper and transformer and a multi-turn coil and field shaper. Metallographic investigation of the samples, hardness tests and leak tests were executed to determine the most suitable machine set-up and the optimal input parameters for each set-up. A second major goal is to determine the influence of the target tube wall thickness on the deformation of tube-tube welds when no internal support is used.

2017 ◽  
Vol 8 (1) ◽  
pp. 7
Author(s):  
Barbara Simoen ◽  
Koen Faes ◽  
Wim De Waele

Magnetic pulse welding is an innovative joining method which allows joining of dissimilar metal combinations. However, much remains unknown about the process and its parameters. In this paper, the weldability of copper tubes to steel rods and tubes is discussed, with the goal of examining the influence of the wall thickness of the supporting steel tube on the weld and the deformation of the components. Large deformations were observed, causing an undesirable decrease in diameter of the tubes. The quality of the obtained welds was shown to decrease with decreasing inner tube thickness as well, most likely due to the deformation of the workpieces in radial direction. Because of this, it is advisable to use an internal support to prevent deformation of the support tubes. To gain more insight in the precise mechanisms of weld formation and failure, numerical simulations are advised.


Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 997 ◽  
Author(s):  
Omid Emadinia ◽  
Alexandra Martins Ramalho ◽  
Inês Vieira de Oliveira ◽  
Geoffrey A. Taber ◽  
Ana Reis

Magnetic pulse welding can be considered as an advanced joining technique because it does not require any shielding atmosphere and input heat similar to conventional welding techniques. However, it requires comprehensive evaluations for bonding dissimilar materials. In addition to processing parameters, the surface preparation of the components, such as target material, needs to be evaluated. Different surface conditions were tested (machined, sand-blasted, polished, lubricated, chemically attacked, and threaded) using a fixed gap and standoff distance for welding. Microstructural observations and tensile testing revealed that the weld quality is dependent on surface preparation. The formation of waviness microstructure and intermetallic compounds were verified at the interface of some joints. However, these conditions did not guarantee the strength.


Sensors ◽  
2020 ◽  
Vol 20 (20) ◽  
pp. 5925
Author(s):  
Voitech Stankevic ◽  
Joern Lueg-Althoff ◽  
Marlon Hahn ◽  
A. Erman Tekkaya ◽  
Nerija Zurauskiene ◽  
...  

The possibility of applying CMR-B-scalar sensors made from thin manganite films exhibiting the colossal magnetoresistance effect as a fast-nondestructive method for the evaluation of the quality of the magnetic pulse welding (MPW) process is investigated in this paper. This method based on magnetic field magnitude measurements in the vicinity of the tools and joining parts was tested during the electromagnetic compression and MPW of an aluminum flyer tube with a steel parent. The testing setup used for the investigation allowed the simultaneous measurement of the flyer displacement, its velocity, and the magnitude of the magnetic field close to the flyer. The experimental results and simulations showed that, during the welding of the aluminum tube with the steel parent, the maximum magnetic field in the gap between the field shaper and the flyer is achieved much earlier than the maximum of the current pulse of the coil and that the first half-wave pulse of the magnetic field has two peaks. It was also found that the time instant of the minimum between these peaks depends on the charging energy of the capacitors and is associated with the collision of the flyer with the parent. Together with the first peak maximum and its time-position, this characteristic could be an indication of the welding quality. These results were confirmed by simultaneous measurements of the flyer displacement and velocity, as well as a numerical simulation of the magnetic field dynamics. The relationship between the peculiarities of the magnetic field pulse and the quality of the welding process is discussed. It was demonstrated that the proposed method of magnetic field measurement during magnetic pulse welding in combination with subsequent peel testing could be used as a nondestructive method for the monitoring of the quality of the welding process.


2019 ◽  
Vol 6 ◽  
pp. 7
Author(s):  
Verena Psyk ◽  
Maik Linnemann ◽  
Christian Scheffler

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.


2018 ◽  
Vol 767 ◽  
pp. 431-438 ◽  
Author(s):  
Joerg Bellmann ◽  
Joern Lueg-Althoff ◽  
Sebastian Schulze ◽  
Soeren Gies ◽  
Eckhard Beyer ◽  
...  

Magnetic pulse welding (MPW) is a promising technology to join dissimilar metals and to produce multi-material structures, e.g. to fulfill lightweight requirements. During this impact welding process, proper collision conditions between both joining partners are essential for a sound weld formation. Controlling these conditions is difficult due to a huge number of influencing and interacting factors. Many of them are related to the pulse welding setup and the material properties of the moving part, the so-called flyer. In this paper, a new measurement system is applied that takes advantage of the high velocity impact flash. The flash is a side effect of the MPW process and its intensity depends on the impact velocity of the flyer. Thus, the intensity level can be used as a welding criterion. A procedure is described that enables the user to realize a fast parameter development with only a few experiments. The minimum energy level and the optimum distance between the parts to be joined can be identified. This is of importance since a low energy input decreases the thermal and mechanical shock loading on the tool coil and thus increases its lifetime. In a second step, the axial position of the flyer in the tool coil is adjusted to ensure a proper collision angle and a circumferential weld seam.


2017 ◽  
Author(s):  
Chady Khalil ◽  
Yannick Amosse ◽  
Guillaume Racineux

2019 ◽  
Vol 110 ◽  
pp. 01008
Author(s):  
Evgeny Strizhakov ◽  
Stanislav Nescoromniy

Various techniques for producing fixed joints in solid using electromagnetic fields are considered; basic diagrams, physics, features, and technical capabilities of each method are described. It is shown that thin-walled tubular irregular structures can be obtained under the magnetic-pulse moulding welding that joins the combined actions of induced currents passing through the overlap zone and magnetic pressure for apposing the weldable edges and for shaping in accordance with the matrix configuration. Obtaining joints from dissimilar materials and structures of different thicknesses is implemented due to shock pulse capacitor welding with magnetic pulse drive. The series connection of the weldable parts enables to synchronize the current flow and force impact on the weld junction. Depending on the combination of the weldable products, three techniques of shock pulse capacitor welding with magnetic pulse drive are proposed. To intensify the quality improvement of the female connectors obtained, it is proposed to use the magnetic-pulse welding in vacuum instead of the diffusion welding. Preheating of the complete unit in vacuum allows for the pre-activation of the connectable surfaces. A unique feature of the implemented diagram is a remote action on the telescopic joints of dissimilar alloys heated in vacuum to the pre-melting temperatures through a quartz glass.


2016 ◽  
Vol 879 ◽  
pp. 1662-1667 ◽  
Author(s):  
Thaneshan Sapanathan ◽  
Kang Yang ◽  
Dmitrii Chernikov ◽  
Rija Nirina Raoelison ◽  
Vladimir Gluschenkov ◽  
...  

Magnetic pulse welding (MPW) is a solid state joining process, successfully utilized to join dissimilar metals. This advantage attracted manufacturing industries to fabricate hybrid materials to attain materials with a combination of multiple attributes. The high speed impact during the welding process causes various interfacial phenomena, which have been reported in previous research studies. Combined high speed collision, Joule heating due to eddy current and plastic heat dissipation cause noticeable heating in the workpiece. The heating from the plastic work and collision energy could particularly be significant at the vicinity of the interface compared to other regions of the workpiece. The Joule heating due to eddy current affects the entire workpiece that is prominent before the collision. There is a sharp increase of the temperature at the onset of weld formation due to dissipation of plastic work during the collision. 3D simulations of coupled electromagnetic-mechanical-thermal were carried out to investigate the heating due to the combined Joule heating and plastic dissipation. A case study of MPW, consist of a one turn coil combined with a field shaper, is used to investigate the welding process. The simulations were performed using LS-DYNA®, which has the capability of using both finite and boundary elements to solve the thermo-mechanical problem during electromagnetic forming. The predicted temperature distributions from numerical simulations show expected phenomena of Joule heating and plastic heat dissipation while the analytical approach used to estimate the localized increase in temperature due to supersonic gaseous compression. Minimizing the heating effect by identifying the influencing factors could help to optimize and control the quality of the magnetic pulse welded parts.


Author(s):  
Yangfan Qin ◽  
Hao Jiang ◽  
Guangyao Li ◽  
Junjia Cui

: With the increasing applications of multi-material structures in lightweight vehicle, traditional joining techniques are highly challenged in joining dissimilar materials. To meet the requirements of the multi-material structure of lightweight design, electromagnetic joining (EMJ) technology including electromagnetic riveting (EMR) and magnetic pulse welding (MPW) developed rapidly in recent years, which can achieve good connection performance for complex-shaped structures and dissimilar materials. This paper presents a comprehensive review of the research progress of the EMJ technology in China. Moreover, this review aims at providing a guideline for researchers engaged in electromagnetic joining technology and other connecting processes to further improve the level of lightweight vehicle design and manufacture. Firstly, the development history and status of EMJ was presented. Then the basic joining principles and characteristics of EMR and MPW were analyzed in detail. Subsequently, the investigation of joints formation mechanism, mechanical properties of joints and equipment development of EMR and MPW techniques were reviewed and analyzed. Especially, the operating principle is described along with various factors affecting the mechanical and microcosmic properties of joints. Finally, the future development trend of the EMJ technology based on the current research progress is highlighted.


Author(s):  
Shunyi Zhang ◽  
Joern Lueg-Althoff ◽  
Marlon Hahn ◽  
A. Erman Tekkaya ◽  
Brad Kinsey

Abstract Magnetic pulse welding (MPW) is a solid-state welding process that bonds similar and dissimilar metals using a high velocity collision. In this paper, effects of impact velocity, target tube thickness, and mandrel inclusion on the interfacial morphology were investigated through the welding of tubular parts, Al6060T4 (flyer) to Cu-ETP (target), by electromagnetic compression. The hypothesis tested in this research is that a “well-supported target,” i.e., either a thick target or the support of a mandrel, allows for vortices to be created at the interface during MPW provided that the impact velocity is sufficient. The mandrel used in the experiments was polyurethane with a Shore hardness of 92A, which was pre-stressed via a washer and nut. The impact velocity was measured via photon Doppler velocimetry (PDV) and used for the setup of numerical simulations. A 2D axisymmetric numerical model was implemented in LS-DYNA to predict the interfacial morphology. Thermal analyses in the numerical model were used to predict the local melting locations and compared with experimental observations. Both experimental and numerical results showed that the interfacial wavelength increased with an increase in the impact velocity and target thickness. Similarly, a thin target with mandrel support also caused an increase in the wavelength. Vortices were only generated with appropriate impact velocities and well-supported targets, i.e., again either a thick target or the support of a mandrel.


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