Magnetic Pulse Welding Technology

2010

The magnetic pulse welding (MPW) is a cold weld process of conductive metals to the similar or dissimilar material combination. MPW uses magnetic pressure to drive the primary metal against the target metal sweeping away surface contaminants while forcing intimate metal-to-metal contact, thereby producing a weld. In the most of the previous paper and research report the conventional MPW method was introduced for the tubular or cylindrical components. On the other hand, only a few papers on MPW of sheet work-piece have been reported. This paper describes a novel MPW technique for dissimilar sheet metal joints and its experimental results. In our experiments, the MPW formation in the dissimilar joining of Aluminum/Fe (SPCC), Aluminum/Ti and Aluminum/Mg (AZ91D) were investigated.

MATEC Web of Conferences, 2018

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 easily reach several hundred millimetres in length, but only a few millimetres in width. If a larger connected area is required, incremental or sequential magnetic pulse welding is a promising alternative. Here, the inductor is moved relative to the joining partners after the first weld sequence and then another welding process is initiated. Thus, the welded area is extended gradually by arranging multiple adjacent weld seams. This paper demonstrates the feasibility of incremental magnetic pulse welding. Furthermore, the influence of important process parameters on the component quality is investigated and evaluated in terms of geometry and micrographic analysis. Moreover, the suitability of different mechanical testing methods is discussed for determining the strength of the individual weld seams.

Welding journal, 2007

Magnetic pulse welding (MPW) is a cold process for welding conductive metals to similar or dissimilar materials. Magnetic pulse welding uses magnetic pressure to drive the primary metal against the target metal sweeping away surface contaminants while forcing intimate metal-to-metal contact, thereby producing a solid-state weld. In this paper, the MPW method and its application for several aluminum alloys (A1050, A2017, A3004, A5182, A5052, A6016, and A7075) and joints in steel (SPCC) sheets were investigated, and the welding process parameters and characteristics are reported.

This work investigates the study of the experimental weldability in magnetic pulse welding process of a one material assembly (aluminium AA6060T6) and a dissimilar metal couple (aluminium6060T6/copper). The weld quality is defined using a destructive process allowing measuring the weld dimension. A diagram charging voltage-air gap is used to establish the variance of weldability. With the criterion of width of the weld, this representation is able to determine the operational weldability window. The lower boundary is defined by the case of bad weld, i.e. an insufficient bonding, and the upper boundary by the case of detrimental weld, i.e. a weld susceptible to crack. The weld is able to undergo a plastic deformation prior to failure. A large weld is more potentially ductile. A numerical modelling of a mechanical destructive push out test could be helpful to characterise the weld in a quantitative manner. Finally, the material dissymmetry as considered in this study notably reduces t...

Almost 50 years after magnetic pulse welding was invented, it is finally finding its way to the private sector, in particular the transportation and refrigeration industries. To support this evolution, more fundamental and applied knowledge on magnetic pulse welding has to be established. Learning from the explosive welding process which is very similar and already thoroughly studied and documented, is one way of achieving this. This paper first discusses why both processes are alike, but not the same. A closer look at the process parameters and especially those of explosive welding learned, that an increasing flyer plate velocity results in a transformation of the bonding interface from smooth to wavy and an increase in hardness at the surfaces of both metals. Welding windows developed for explosive welding are discussed. The reasons for the limitations set to impact angle and collision velocity in a welding window are briefly reviewed. This information can give a hand in the optimization of the parameter settings to achieve sound welds with the magnetic pulse process. To check if a high quality weld is made, several testing methods for both processes are discussed and compared.

2012

This work investigates the study of the experimental weldability in magnetic pulse welding process of a one material assembly (aluminium AA6060T6) and a dissimilar metal couple (aluminium6060T6/copper). The weld quality is defined using a destructive process allowing measuring the weld dimension. A diagram charging voltage-air gap is used to establish the variance of weldability. With the criterion of width of the weld, this representation is able to determine the operational weldability window. The lower boundary is defined by the case of bad weld, i.e. an insufficient bonding, and the upper boundary by defective welds, i.e. a weld susceptible to crack. The weld is able to undergo a plastic deformation prior to failure. A large weld is more potentially ductile. A numerical modelling of a mechanical destructive push out test could be helpful to characterise the weld in a quantitative manner. Finally, the material dissymmetry as considered in this study notably reduces the weldabilit...

In magnetic pulse welding, electromagnetic pressure is used to deform, accelerate and weld workpieces. The process is mostly used for tubular specimens. In this study, experiments were performed in order to investigate the weldability of copper tubes to brass solid workpieces. The tubes had an outer diameter and wall thickness of 25,0 mm and 1,5 mm respectively. A multi-turn coil with 5 windings in combination with a field shaper was used to focus the electromagnetic flux and thus realize the high pressures needed for welding. The process parameters for joining these materials were optimised for maximum weld length. The parameters taken into account were the position of the field shaper relative to the workpieces, the width of the air gap between the tube and the internal workpiece and the energy level. The weld quality was verified based on metallographic examinations, scanning electron microscopy and hardness measurements.

Manufacturing Review, 2019

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 p...

Journal of Manufacturing and Materials Processing

Lightweight structures in the automotive and transportation industry are increasingly researched. Multiple materials with tailored properties are integrated into structures via a large spectrum of joining techniques. Welding is a viable solution in mass scale production in an automotive sector still dominated by steels, although hybrid structures involving other materials like aluminum are becoming increasingly important. The welding of dissimilar metals is difficult if not impossible, due to their differential thermo mechanical properties along with the formation of intermetallic compounds, particularly when fusion welding is envisioned. Solid-state welding, as with magnetic pulse welding, is of particular interest due to its short processing cycles. However, electromagnetic pulse welding is constrained by the selection of processing parameters, particularly the coil design and its life cycle. This paper investigates two inductor designs, a linear (I) and O shape, for the joining o...

Indian Journal of Science and Technology, 2015

In this paper the joining of two dissimilar metals as Al-SS, Al-Cu and SS-Cu were studied. Commonly, MPW is considered as a non-melting process. Magnetic Pulse machine which is belong to Non-conventional technique instead of conventional technique. Magnetic Pulse Welding (MPW) is a joining process in which lap joint surfaces of cylindrical shape metals, such as pipes and tubes, are welded by impact, using electromagnetic forces. MPW is classified in the group of solid-state bonding processes together with Explosive Welding (EXW). The technique has become an unique and acknowledged welding process because it enables to join similar, as well as dissimilar metals, which is very difficult to weld by traditional methods such as GTAW or EBW due differences in melting points etc. MPW process is very fast, produces no Heat Affected Zone (HAZ) and may be performed without filler metals and protective gases. Nevertheless, it was detected a very thin film (10 to 50 µm) of two welded metals in the form of intermetallic phases, in which melting and solidification processes took place. These inter-metallic phases significantly affect the mechanical properties of the joint. The diffusion of elements in the intermetallic phase was studied for the pattern and the composition of the blended metals and formation of pores etc. The interface typically presents a wavy pattern and mutual diffusion of elements happens in the transition zone. The transition zone is composed of elements intermetallics, micro cracks and micro pores as expected in our study. The effect of the parameters on the morphology, configuration and structure of the interface has been thoroughly studied. The weld interface composition, structure and morphology were studied by optical and Scanning Electron Microscopy (SEM). Energy-Dispersive Spectrometry (EDS) was used in order to evaluate the local distribution of alloying elements at the joint interface and its vicinity and also nano-hardness tests were performed across the bonding zone at regular increments. The results of the joints were analysed for process parameters and based on the result , the process parameters has to be reviewed accordingly to yield best interface weld results.