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Patching is a high-technology repair to preserve damaged jet engine blisks instead of replacing them. The damaged portion of the blade is restored by welding a patch to the blade. Since the extent ...

Manufacture of a transition hybrid coupling from two different steels, medium carbon S355J2 and stainless 316L, has been demonstrated using two different solid-state joining routes, forge welding (FW) and rotary friction welding (RFW). An additional manufacturing route, electron beam welding (EBW), was also employed in investigating its feasibility for such application. Mechanical and microstructure properties of the final components manufactured from the three different routes have been compared. Finite element (FE) analysis was utilised to determine optimal geometries for the FW and the RFW preform rings and identify optimal parameters for both processes. Of the three manufacture routes, the FW produced an instant diffusion-like bond with a single forging stroke on a 2100T screw press with the thinnest weld interface and most uniform hardness distribution at either side of the joint. The RFW part, manufactured on a 125T RFW machine, also exhibited a very thin weld interface, yet slightly thicker compared to the FW case, with small variations in the hardness distribution at either side. The EBW produced markedly thicker weld interface compared to the two solid-state routes. The EBW part exhibited significant variation in hardness distribution across the weld exhibiting peak hardness in the weld indicating requirements for a post-weld heat treatment (PWHT). Both the FW and the RFW process routes exhibited very uniform micro-hardness and microstructures across the weld interface in contrast with the EBW process in as-manufactured condition.

High heat flux components form the primary interface for thermal management of injectors in fusion devices. The requirement for such application varies from 1 to 10 MW/m2. Ultra-high-vacuum compati...

We are living in a time where the emphasis is given on the development of new and improved materials having high strength and are correspondingly light in weight for application in fields such as transportation, aerospace, medical and other such related areas. These new materials developed need to be processed and joined with oneself and other materials as well. The paper presents a brief understanding of the advanced joining processes namely friction stir welding, microwave hybrid heating, electron beam welding, laser beam welding, thermo-hydrogenated diffusion bonding, electromagnetic welding and ultra sonic welding. The purpose of these advanced joining techniques is to increase the efficiency of the joining process and prevent failure. The objective of this review paper is to provide an insight into the principles, current trends and research gaps in advanced joining techniques.

A boost in the preference of high energy beam, such as electron beam, laser beam etc. has led to the requirement of its automation through accurate input–output modelling. Modeling of electron beam welding is conducted in the present study through Elman and Jordan recurrent neural networks (RNNs), both having a single feed-back loop, to meet the said requirement. The RNNs are trained using some nature-inspired optimization tools, namely cuckoo search, firefly, flower pollination, and crow search utilizing input–output welding data, obtained from a computational fluid dynamics-based heat transfer and fluid flow welding model. RNN predictions are validated through real experiments. Thus, the effect of change in the position of the feed-back loop on the accuracy of prediction of RNNs is investigated. In addition, a few popular statistical tests have been used to evaluate the performances of the RNNs tuned by various optimization algorithms, where flower pollination-tuned Jordan RNN is observed to yield the best results.

A new generation of electron beam tool for welding during assembly and repair-restoration works on board of manned space vehicles in open space was demonstrated. The tool includes a small-sized electron beam gun (EBG) with an electron beam power of up to 2.5 kW and a high-voltage power source with a voltage of 10 kV. The design of the electron-optical system of EBG allows using it in both manual as well as in automatic mode applying robotic devices. Applying the manufactured EBG and manipulator, in vacuum chamber the works on simulating the repair of a spacecraft’s section of aluminum 2219 alloy were carried out. The obtained results of studying the structure and mechanical characteristics and also sealing of welds confirmed the high quality of welded joints and a reliability of the technology for repairing a damaged fragment of a spacecraft's body using electron beam welding.

In many cases, both laser and electron beam welding may be considered for critical applications involving a wide range of structural materials. The ability to use both processes to make comparable welds in terms of both weld profile (penetration) and microstructure provides considerable process selection flexibility. In this study, autogenous, partial penetration welds on 304 and 304L SS were made using both fiber laser and electron beam processes. To simplify the analysis, many parameters were kept constant between processes, including working distance and spot size. The main variables, power and travel speed, were varied individually. Beam analysis was conducted using a PRIMES Focus Monitor to characterize the laser beam and a pro-beam diagnostic tool (PBD) for the electron beam. Electron beam welds were deflected or defocused to achieve a spot size similar to that of the laser welds, approximately 500 μm. The deflection pattern chosen for electron beam welding was made to mimic the power distribution of the laser. A similar melting efficiency at varying powers and travel speeds was maintained for both processes. Geometries and microstructures of the deflected and defocused electron beam welds and the laser beam welds are compared and related to process parameters.

In the automobile industry, the reduction of the overall weight of vehicles faced a global challenge in terms of achieving better fuel economy and reducing the co2 emission levels. Aluminum alloys are widely used in the automotive industry due to their high strength to weight ratio than steel. In recent years, high strength aluminum alloy sheets are used in the aeronautical and automotive industries for constructing body structures. However, joining this high-strength aluminum alloy during mass production is difficult by using conventional welding processes. The family of intense energy welding like plasma arc welding, electron beam welding, and laser beam welding is generally employed to weld the high-strength aluminium alloys. This study aims in evaluating and selecting the best intense energy welding process to produce high strength aluminum alloy joints for automotive application by using the Analytical Hierarchical Process (AHP). Thus, the proposed AHP model was also verified with SuperDecision v3.2 software.

The paper treats problems of reducing the cost of welding and improving the quality and productivity of welding parts of cold-resistant steel of great thickness during the construction of oil platforms. The design of tooling structure and devices for electron-beam welding have been developed such as a welding wire feeder, a video observation system, and software for controlling the workpiece movement and the electron beam gun travel.

The concept of creating electrical insulating ceramic materialsproducts from powder systems representing oxide and nonoxide chemical compounds was formed; a program document for materials science and technological logistics of physical and chemical transformation of technogenic mineral raw materials into electrical materials-products of various scientific, practical and specific technological purposes was created and implemented. The principal theoretical approach and its appliedpractical aspects of the development - research - creation of thermo- and chemically resistant structural electrical insulation materials - products for various scientific and practical purposes: automatic contact welding of tubular bimetals (for example, copper - aluminum), electron beam welding in vacuum of thickwalled large-sized structures made of high-strength aluminum alloys, high-temperature (1050 oC) hardening of drilling tools in vacuum furnaces in the medium of dissociated acetylene are considered, in electric transmissions of brake installations of quarry dump trucks (k/s) BelAZ.

In the present study, machine learning algorithms have been used to predict residual stress during electron beam welding of stainless steel using the information of input process parameters and natural frequency of vibrations. Accelerating voltage, beam current and welding speed have been considered as input process parameters. Both residual stress and natural frequencies of vibration of the weld obtained using each set of the input parameters are measured experimentally. A number of machine learning algorithms, namely M5 algorithm-based Model Trees Regression, Random forest, Support Vector Regression, Reduced Error Pruning Tree, Multi-layer perceptron, Instance-based k-nearest neighbor algorithm, and Locally weighted learning have been used for the said purpose. Support vector regression and Locally weighted learning are found to perform consistently good and bad, respectively. The predicted welding residual stresses have been validated experimentally through X-ray diffraction (XRD) and good agreements are obtained. In addition, statistical tests are conducted, and the estimated reliability values of the employed models are analyzed through Monte-Carlo simulations.

The concept of brittle crack arrest has recently become an internationally focused issue for container ships. The International Association of Classification Society (IACS) also prescribed the unified requirement (UR) for brittle crack arrest design, and brittle crack arrest design has been internationally authorized. As one of the methods to evaluate brittle crack arrestability, the crack arrest temperature (CAT) concept, by isothermal crack arrest test, has been proposed since the 1990s. The concept has been applied mainly for tank design. However, no standard has been specified to describe the detailed evaluation procedure. This means that only limited organizations can evaluate CAT and it is considered to be a problem when arrest evaluation is mandated as an international standard. In the background of such circumstances, Japanese research groups including the Japan Welding Engineering Society (JWES) and Nippon Kaiji Kyokai (ClassNK) started the standardization for CAT test in 2016. In the research programme, various aspects of control factors have been investigated based on the test results from many experiments and numerical calculations. The CAT test shall include the embrittled zone to initiate a brittle crack. Either electron beam (EB) line remelting or a local temperature gradient (LTG) can be applied to the embrittled zone. Even if we focus on EB welding only, welding defects in the embrittled zone can be an influencing factor. In this report, we investigate the effects of residual stress by EB welding on the crack driving force, which is quantified as the K value using a 3D finite element method (FEM). As a result, we confirmed the existence of the residual stress which cannot be ignored that is formed on the surface of the EB-welded portion; however, the influence of that on the K value is considered to be small if the CAT test conditions can sufficiently secure the arrest crack length. This result shows that the driving force at the arrested point in the CAT test can be simply evaluated by the LEFM formula without consideration of the residual stress of the EB weld for embrittlement.

The China Fusion Engineering Testing Reactor (CFETR) vacuum vessel (VV) port stub was formed by electron beam welding (EBW). In this article, the phased array ultrasonic testing (PAUT) method was introduced for testing the quality of the weld. First, the acoustic field simulation and analysis of the EBW of 316L austenitic stainless steel were carried out with different frequency probes, then the microstructure of electron beam welds were observed by microscopic metallographic to analyze the influence of the type and influence of probe, finally fabricating the reference test blocks according to the NB/T47013-2015 standard to conducting the PAUT experiment. The test results show that the type of probe has less influence on the signal-to-noise ratio (SNR) and localization of the detection of large-thickness austenitic stainless steel electron beam welds under low-frequency conditions. The SNR of EBW detection was gradually decreased as the frequency of the probe increases under the same type of probe. In the direction of depth of the EBW, with the increase in the depth, the weld microstructure size becomes finer, so the sector scan image of $\phi ~1$ -mm side drilled hole (SDH) near the upper weld was severely distorted, while the sector scan image of $\phi ~1$ -mm SDH near the lower EBW was relatively good.

The research shows the possibility of increasing the structural strength of the weld joints of EP517 steel and 36NKhTYu iron-nickel alloy as applied to the combined bandage of the high-speed rotor of an electric machine, due to the effect of local strengthening of the soft interlayer. The technology of electron-beam welding of 36NKhTYu alloy to EP517 steel with free root formation, which allows to obtain narrow welds, is described. The results of metallographic researches and mechanical tests of weld joints with different weld widths are presented, which showed that the structure and properties of the weld metal on samples with different weld widths are almost identical. The tension test results of weld joints demonstrate a significantly greater ultimate tensile stress, compared to the ultimate tensile stress of the weld metal. Also, it was established that, due to the local strengthening phenomena the smaller the weld width, the stronger the welded joint is. In addition, the use of heat treatment after welding allows us to increase the strength properties of the weld metal and the heat-affected zone of the 36NKhTYu alloy, due to the formation of the hardening γ’-phase. The possibility of increasing the ultimate tensile strength of the weld up to 98% of the ultimate tensile stress value of EP517 steel (as the less durable of both welded materials), due to heat treatment and reducing the weld width, is demonstrated.

Beam welding processes such as electron beam or laser beam welding are used for a range of applications where precise and localised heat input is required. In this contribution, two industrial beam-welding facilities were used to produce joints with a maximum depth of 25 mm. The materials investigated were 42CrMo4 QT-steel and S355 structural steel. The investigations show that both beam welding processes led to comparable results. The butt joints generated were rated by means of macroscopic and microscopic characterization methods. The mechanical properties were investigated by static tensile and Charpy notched bar impact testing. Both beam sources exhibited characteristic features when joining the steels. Due to the smaller beam diameter of the laser, laser welded seams were 40 % to 50 % smaller than their electron beam welded pendants. The reduction of the tensile strength of the initial state was below 4 % for both welding techniques.

The economic efficiency of die-casting processes is largely determined by the lifetime of the die. Such dies are exposed to high cyclical loads of thermal, mechanical, tribological and chemical loads during operation. These loads cause various types of damage, which reduce the lifetime. If the production comes to an unexpected stop due to a critical defect in the casting tool, repair welding is often the only way to return the tool to production immediately. At present, primarily manual TIG or plasma-welding processes are used for this purpose, which, however, exhibit insufficient process reliability and thus achieve an insufficient extension of lifetime. The primary objective of the research project is therefore the development of a technology for the economical regeneration of locally damaged die-casting dies with improved metallurgical properties compared with conventional repair welds. This forms an elementary basis for extending the service life of dies in series production. For this reason, electron-beam welding is to be qualified because of its possibilities for variable, need-adapted designs of the overall heat balance and the use of filler material as a welding process for industrially used hot-work steels.

Applying and improving electron beam welded (EBW) joints to newly developed high-alloy TRIP/TWIP steels requires in-depth knowledge of the underlying physical phenomena. In an effort to further understand such phenomena, a CFD model is developed in the free, open source CFD software OpenFOAM. Its goal is to provide a basis for gaining deeper insight into the thermofluid-dynamical processes, which includes heating, melting, weld pool fluid dynamics, vaporization, solidification and cooling. For this purpose, a combined double-ellipsoid conical heat source (HS) is implemented into an existing finite volume solver to model the heat input of the electron beam (EB) into the weldment. As the HS is accompanied by a variety of free parameters, those parameters are adjusted to reproduce the shape of experimentally welded joints. Complete sets of parameters are presented accordingly. Furthermore, the thermophysical properties are implemented temperature-sensitive in order to account for the strong temperature gradients affecting heat transport. Since the solidified material is saved as an extra field in order to distinguish it from the parent metal, the seam geometry can be evaluated following the simulation. The resulting simulated weld cross section shows noteworthy good agreement compared to the experimentally obtained full penetration seam. Moreover, the typical teardrop shape of the weld pool is obtained in the simulations, so the usual approach of elongating the HS in its rear part is not necessary. Since the developed model is capable of reproducing the seam development during EBW, it could eventually be used to implement and investigate additional physical effects.

Various types of scanning can enhance the quality of welding joints, which allows us to control the energy distribution of the electron beam. In the study conducted by the authors, it was experimentally revealed that the best quality of welded joints is obtained by scanning an electron beam in the form of a sinusoidal raster. The research was conducted for thin-walled aerospace structures. Equipment was developed that realizes scanning in the form of different rasters, considering the frequency of the sweep, thereby removing the high frequency, which will allow getting a more even “saw”. As the different types of scanning shapes at which the optimization was carried out, the next types were used: a classical raster, a sinusoidal raster and a truncated raster. The obtained results allow a more meaningful approach to the process of electron beam welding of different types of materials and thin-walled structures and obtaining a consistent seam quality.

Electron beam welding (EBW) is a high-end manufacturing method often used in aerospace, defence and nuclear sectors. In order to explore the feasibility of upgrading the conventional EBW process to smarter and intelligent manufacturing towards Industry 4.0, this paper presents a computational fluid dynamics (CFD) model, where the e-beam characteristics are obtained through a state-of-the-art beam probing system, to simulate the electron beam welding of pure niobium plate with a circular beam deflection pattern. The effect of beam oscillation is studied based on the experiments and simulation results including weld bead shape, penetration, temperature distribution, keyhole generation, etc. It can be concluded that electron beam oscillation can reduce the maximum temperature of the molten pool and inhibit the generation of keyhole, therefore the weld seam quality is greatly improved compared with single path weld. The CFD model could be integrated into a digital toolbox for automating and better controlling the EBW process for a wider range of materials.

Over the past twenty years the Electric Welding Institute named after E.O. Paton has developed and manufactured great number of “general-purpose” machines for EBW, used for welding of various products made of various materials. All these machines may be roughly divided into several types according to the welding chamber volume and therefore the possible sizes of welded products: “small”, “medium”, “large” and “extra large”. They specificity is reviewed briefly in the article. The machines are equipped with an up-to-date 60 kV welding power source of 6 … 60 kW power, depending upon the specific welded materials and their thicknesses. Typically, all machines are completed with the system of secondary-emission electron visualization “RASTR-6”, inseparably integrated into the welding power source. It interacts with an up-to-date control system. The part of equipment, which is exerting influence on the welding process, is under continuous program control. The concept of high-level software control, in which the user interacts with the equipment exclusively via the Windows-oriented graphical user interface, is used. Two basic configurations of the system of numerical control for EBW machines are used. The first uses of a complete industrial system Sinumerik 840Dsl, and the second one uses “short-cut” industrial system Synamics S120. In both cases the interaction of the control programs with executive equipment is carried out using two industrial buses CAN and ProfiBUS.

Raja Ramanna Centre for Advanced Technology (RRCAT) has an ongoing program to develop 650 MHz, 5-cell elliptical superconducting RF (SCRF) cavities under the Indian Institutes and Fermilab Collaboration. The elliptical multi-cell SCRF cavity fabrication process involves forming of half-cells and their precise machining and joining by electron beam welding to form end groups and dumbbells, which are then joined to make the final cavity. To ensure that the final welded cavity achieves physical lengths and resonant frequencies within design tolerance and has good field flatness, the measurement and correction of resonant frequency are carried out for dumbbells and end groups. A novel method to identify the frequency of individual half-cells in a dumbbell cavity and a dedicated tuning fixture to correct them had been developed. The paper details the RF characterization and correction procedure employed during fabrication of the first six 650 MHz cavities at RRCAT.

Beam Position Monitors (BPM) are non-destructive diagnostics devices used in particle accelerators to measure the transverse beam position (beam center of mass) and phase of the accelerated beam. There are various ways of realization of the BPMs in accelerators having different measurement requirements, particle type or energy. Several types of BPM pickups have been studied including the button type, grounded striplines and matched striplines. The choice and final design is based on a matched stripline to accommodate the signal transmission to electronics and provide relatively higher signal level for low velocity ( β = 0 .088) proton beam within MEBT. Due to mechanical space limits, all the BPMs are embedded inside quadrupoles; hence it is required to use non-magnetic materials in the BPM sensor, in particular the feedthroughs. The BPM sensor is composed of several components, which are separately machined with tolerances of 10 μ m , and then welded together by the use of electron beam welding. The analysis show for long bunches, the multi bunch transfer impedance is different than of single bunch due to bunch signals overlapping. The design, fabrication and tests of the BPM sensors were performed at ESS-Bilbao and their installation and the electrical checks at ESS-Lund. Prior to installation in the ESS accelerator tunnel, one BPM stripline was installed and the BPM system tested with the CEA-IPHI beam. This paper gives an overview of the electromagnetic and mechanical design and the fabrication of BPM striplines. Furthermore, the results of the RF measurements are compared with the simulations.

In the article is considered automation task entering the beam at electron beam welding . During the course of research was developed flow chart to manage it entering an email address a button that shows how it works the process itself management. Developed flow chart optimizations input mode the area in which it is located subprocesses are described optimizations welding equipment. Submitted by calculation algorithm distributions temperatures during the input stage e-mail address beam, based on which one and developed by the entire system. Also developed and presented structural and functional model flow chart programs management process welding and window software version management systems. Solution of the task will allow you to not just lower it expenses for working out technological solutions parameters’ electron beam welding of products with a new geometry either of the new one’s materials, but also support decision making technologist at optimizations manufacturing process existing one’s products. In process experimental data research, based on developed by automated systems, carried out modeling distribution energy consumption at entering an email address beam for structures from two different sources materials with different geometries. Developed by automated system the system in the future allows you to consider product dimensions, type of material, spread by temperature, technological features parameters and get more information stable weld quality seam with less quantity root defects.

In electron beam welding a very intense pencil beam of electrons is driven onto the base metal, to melt it and produce the welding. In the interaction of the beam with the metal, strong bremsstrahlung emission of X-ray is generated. Here the generation is evaluated, and the KERMA in air at 1 m is predicted. Results show that a significant radiation hazard is present and serious radiation protection measures are needed.

Low C-steel to Fe-7%Al alloy dissimilar joint by electron beam welding (EBW) was carried out using oscillating beam, without oscillating beam and by increasing welding speed condition. X-ray radiography technique at sub-micron resolution was employed to study the effects of scanning parameters on the defect formation. Detection and quantification of defects within welds were subsequently carried out from radiography images by image processing, segmentation of images and pattern recognition. X-ray radiography images showed the presence of porosity, wormhole and lack of fusion-type defects in the dissimilar joints. Quantitative analysis of weld defects demonstrated that beam oscillation provides better quality weld by decreasing approximately 58% porosity compared to its non-oscillating counterpart and 73% compared to higher welding speed. Wormhole and lack of fusion defects were observed at other two conditions, which did not observe in welds produced by beam oscillation.

Budker Institute of Nuclear Physics produces electron beam welding facilities (EBWF), which are successfully utilized in experiments and low series production (e.g. manufacturing of vacuum chambers for the FAIR project). For the joint quality, it is crucial to deflect the electron beam in sync with the welded sample movement. We present the real-time control system architecture, that consists of a CPU-based high-level programmable interface, and real-time control logic implemented in FPGA. FPGA system consists of synchronized subsystems running simultaneously - execution of specialized programs to control electron beam deflection, coordinate table movement, and also processing image data gathered from secondary electron emission detector. To reduce the labor needed for implementation, the image processing subsystem is written in high-level domain-specific language Caph, thus the resulting image processing VHDL code is autogenerated.

Based on the results of a process simulation, a subsequent structural simulation enables a better understanding of metallurgical effects such as solidification and phase transition. The aim of this work is to establish a relationship between welding parameters, seam geometry, efficiency and intensity distribution of backscattered electrons in order to optimize the simulation. For the exact calculation of the energy conversion inside the workpiece the determination of secondary quantities, which enable a metrological recording of the process efficiency, is indispensable. The voltage generated at the measurement resistor is recorded in a detection unit and provides information on the qualitative differentiation and quantitative detection of backscattered and secondary electrons. The power loss is extrapolated from these data.

Scanning electron beam welding (SEBW) is a very important process for welding of thick plates in aerospace, aeronautical and power industries. However, since the invention of this process, the scanning parameters are typically selected through time consuming and costly trial and error. No existing mathematical criterion can be used to select the optimal parameters due to lack of physical understanding of the welding process. In this study, we developed a three-dimensional mathematical model of SEBW capable of modeling the coupled keyhole and weld pool dynamics for the first time, and used it to understand the underlying physics of the welding process and explore the process optimization criterion of circular mode beam scanning by combining welding experiments and modeling. We showed that beam scanning may not always stabilize the keyhole and weld pool, and may not improve the final weld quality of electron beam welding. However, beam scanning can modulate the movement of high temperature positions on keyhole wall, and contribute to a better uniformity of weld pool dynamics behind the keyhole. For circular beam scanning, we proved that low frequency scanning may lead to more welding defects such as porosity, spiking, and spatters because it increases the tendency of keyhole oscillations as compared to the no scanning case. High frequency scanning could stabilize the keyhole to a certain degree and modulate the fluid flow of the weld pool to make it more regular. Additionally, the scanning radius should be neither too small nor too large. Too small radius may lead to more defects, and too large radius can decrease the penetration depth significantly. A dual direction energy uniformity (DDEU) criterion was proposed to select the scanning parameters by considering the energy uniformity degree in the welding direction and the transverse direction. It was demonstrated that process parameters including beam scanning frequency and radius can be successfully optimized using the proposed criterion.

The urgency of experimental study of the formation of powerful electron beams in technological electron guns is substantiated. The design of a technological electron gun of ELA type is described and the possibility of adjusting the electrode gap for changing characteristics of the beam being formed is shown. A series of experiments on the melting of plates (of steel 30 and titanium alloy VT6Сh (Fe up to 0.4%; C up to 0.1%; Si up to 0.07%; V = 3.5-4.5%; N up to 0.05%; Ti = 87.62-90.63%; Al = 5.5-6.75%; O = 0.07-0.2%; H < 0.01%; other elements up to 0.3%) were carried out, during which the electrode gap was varied. Analysis of obtained macrosections of melting regions is made and conclusions about the effect of magnitude of the electrode gap on the shape and transverse dimensions of melting regions are drawn.

Due to physical properties like high thermal and electrical conductivity, joining of copper is of special interest in steelmaking or electrical industry. Unfortunately, joining of thick-walled copper components using electron beam welding (EBW) tends to welding defects like insufficient root formation or varying penetration depth. In previous investigations, Cu-DHP (deoxidised high phosphorus copper) plates were successfully joined by EBW utilising a CuSn6 sheet as filler material. The investigation resulted in a stable EBW parameter window. Nevertheless, using CuSn6 sheets lead to challenges concerning joint preparations, and is not usable for arbitrary weld configurations. To meet these challenges, atmospheric plasma spraying (APS) is used to apply a thin interlayer in the welding zone and substitute the CuSn6 sheet filler metal. This continuative work includes further improvements of the main EBW parameters and uses APS as a new approach for filler metal deposition. Furthermore, determining and enhancing the service properties of the copper joints is of main interest and reported here.

The increased use of electromobility due to ecological and financial motives confronts many enterprises and scientific communities with new challenges. The future viability of this technology is, among other things, depending on the electric range and on the purchase price of the electric vehicle. In addition to research work in the field of battery technology, the automotive industry is focusing on the reduction of the overall weight, the production complexity, and the production costs in order to increase fuel consumption and the range of electric vehicles and, moreover, to make electromobility more affordable. Due to the favorable ratio of strength and dead weight, aluminum die casting parts provide, in combination with the appropriate joining technology, the required preconditions for lightweight construction. The die casting process allows a large-scale manufacture. In the present study, the welding of the aluminum die casting alloy AlSi10MnMg, which is frequently used in automotive engineering, is investigated using the electron beam in atmosphere. At that, different casting quality scenarios are set with the aid of the die casting process and the robustness of the joining method is investigated with regard to die casting imperfections. The analyses are based on results of mechanical and chemical test methods.

This paper presents a novel Nb superconducting joint with an ultralow resistance of 7.9 × 10−16 Ω, fabricated using the electron beam welding (EBW) method. After the EBW process, the two Nb filaments formed a single joint with a much larger grain size and smaller grain misorientation. More importantly, the resistance of the EBW Nb joint was nearly one magnitude lower than that of most conventional pressing joint. The ultralow resistance is essential for superconducting gravimeters, which require an extremely low drift rate. The EBW Nb joint allowed the superconducting gravimeter to have a much better performance when applied in the field of structural geology, geodesy, microgravity, and metrology. We believe that the EBW method could be one of the most promising joint fabrication methods for achieving maximum stability (less than 1 μgal yr−1).

The article discusses electron beam welding for connecting pipelines. This approach has been reviewed in the literature. The technology of creating flange connections in the oil and gas industry is considered. The analysis and selection of the most suitable equipment for the creation of permanent joints of complex structures has been carried out. Thus, a literature-patent review of the current state and methods of using electron beam welding for various designs and control methods has been carried out. The analysis of the subject area showed that there is equipment, in particular, the TETA 6E400 installation and a turntable for creating such connections in the area under consideration. The proposed approach will improve the quality of flange-pipeline welded joints and reduce the cost.

The energy spectra of the ion saturation current of the Langmuir probe in the plasma formed over the keyhole directly during the process of electron-beam welding of steel 09G2S with the varied parameters (e.g., the welding speed and focus coil current) has been investigated. The presence of typical zones with the energy spectrum peaks in the low-frequency and high- frequency bands has been shown. It has been established that the peak location in the high- frequency range of the energy spectrum does not depend on the welding modes and the position of the probes relative to the keyhole. The low-frequency range of the energy spectrum depends on the vapor flow density of the keyhole and is rather sensitive to the welding modes. The use of electron beam oscillation makes it possible to control plasma flows and hydrodynamic processes in the penetration channel.

The first in-house, 9-cell, superconducting radio-frequency cavity made of large grain Nb was fabricated at KEK. Some characteristic techniques were employed for the fabrication that were not used for fine grain (FG) Nb. Even though a penetrated hole was created during electron beam welding, it was successfully repaired and did not affect the cavity performance. The completed cavity then underwent vertical tests (VTs) via several surface treatment processes. A defect that caused quenches was found after a VT at 25 mm from the equator where the typical local grinding machine developed at KEK could not be utilized. A new local grinding machine using a 3D printer was thus developed for the first time, and it completely removed this defect. Finally, the cavity achieved a maximum Q 0 value of 3.8 × 1010 and accelerating gradient of 38 MV/m. The obtained Q 0 value is about 1.5 times higher than that for the KEK in-house FG cavity.

Indian negative-ion source development program has gained momentum with planned integration of Indian Test Facility (INTF) for International Thermonuclear Experimental Reactor (ITER)—Diagnostic Neutral Beam (DNB) characterization at the Institute for Plasma Research (IPR). Eight RF driver-based negative-ion source, being developed for DNB will be tested and operated in INTF. The Two driver-based Indigenously built Negative ion source (TWIN) source provides a bridge between the operational single driver-based negative-ion source test facility, ROBIN in IPR, and an ITER-type multidriver-based ion source. The source is designed to be operated in continuous mode with 180 kW, 1 MHz, 5-s on/600-s off duty cycle and also in 5-Hz modulation mode with 3-s on/20-s off duty cycle for three such cycles. The complete design of TWIN source and its test facility, from conceptual to detailed engineering, has been carried out in IPR. The manufacturing design has been optimized to match the capability of Indian manufacturers, without compromising on the specifications. Some examples of optimization are: 1) an improvised design of the Faraday shields where electrodeposition has been replaced by vacuum brazing; 2) a simplified design of the side walls of the plasma source, where jointing process is simplified, without the application of Electron Beam Welding; and 3) introduction of a fiber reinforced polymer-based integrated electrical and vacuum isolation scheme that replaces the application of a large ceramic. Finite-element analysis (FEA) based on heat load and structural load calculation ensure the functionality and structural integrity of each component of the source. Due to nonnuclear environment in TWIN source experimental area, vacuum brazing is an acceptable manufacturing process. The contract for manufacturing of the ion source has been awarded to an Indian manufacturing company for the first indigenous production of a large-size fusion grade ion source. TWIN source is designed in such a way that it can be operated both in air mode (RF driver coil antennas are exposed to air) as well as vacuum mode. (Whole source is immersed inside vacuum.) The TWIN source shall be manufactured as per ASME guidelines for pressure vessel. Experiments on the TWIN source are foreseen in the last quarter of 2015, as all the auxiliary systems such as 180-kW, RF generator system, vacuum vessel with pumping station, cooling water system, data acquisition and control system, and other power supply systems are already installed in the lab premises. This paper discusses the FEA-based engineering design, simplified manufacturing design, manufacturing experience with highlighting quality control, and the system integration activities undertaken for the TWIN source test facility.

In this research work, we consider the problem of sensor selection for the system controlling full penetration mode in electron beam welding. For this, we have investigated four signals from the backside of the workpiece: electron current in root plasma, ion current in root plasma, through-thickness electron current and penetrating bremsstrahlung X-ray. After having done the research we have estimated the advisability of two signals: one for cases if requirements for control precision are high and the other for other cases.

A two-dimensional mathematical model based on volume-of-fluid method is proposed to investigate the heat transfer, fluid flow and keyhole dynamics during electron beam welding (EBW) on 20 mm-thick 2219 aluminum alloy plate. In the model, an adaptive heat source model tracking keyhole depth is employed to simulate the heating process of electron beam. Heat and mass transport of different vortexes induced by surface tension, thermo-capillary force, recoil pressure, hydrostatic pressure and thermal buoyancy is coupled with keyhole evolution. A series of physical phenomena involving keyhole drilling, collapse, reopening, quasi-stability, backfilling and the coupled thermal field are analyzed systematically. The results indicate that the decreased heat flux of beam in depth can decelerate the keyholing velocity of recoil pressure and promote the quasi-steady state. Before and close to this state, the keyhole collapses and complicates the fluid transport of vortexes. Finally, all simulation results are validated against experiments.

The success of electron beam technology is mainly attributed to the immense research and synthesis of basic science and technology in many fields mainly attributed to high voltage engineering, vacuum technology, advanced level computer technology and electron optics. In this paper, a rigorous effort has been made to electrostatically and electromagnetically focus electron beam, generated from a high power electron gun that can be used for various high voltage applications including melting and evaporation of refractory materials, coating applications, electron beam welding, plasma generation and material processing techniques. In this paper, electrostatic focusing is achieved in the pre-anode region by applying suitable potential to gun electrodes and by their appropriate geometric design. Electromagnetic focusing is achieved by applying suitable magnetic field incorporating focusing coils in the post-anode region. This paper illustrates the design of high power 60kW electron gun that successfully focuses the electron beam through simulation by using CST Particle Studio.