10:30-10:50 AM
The Electron Beam as a Tool of Both Nano Science and Micro Technology: From UHV Evaporation to Micro Electron Beam Welding
M.Merkel*, K.Wrobel*, M.Escher*, M.Zobac**, I.Vlcek**, L.Dupak**, F.-H. Roegner***,
G.Mattausch***, A.Reichmann***
*FOCUS GmbH, Huenstetten, Germany
**Institute of Scientific Instruments of the ASCR, Brno, Czech Republic
***Fraunhofer Institute for Electron Beam and Plasma Technology, Dresden, Germany

The electron beam as a highly efficient heating source is well known since its first use for the
melting of tantalum at the end of the 19th century. During the first half of the last century, its ability to evaporate, to drill, and to weld of even refractive metals has been discovered. After the Second World War people started to use this exciting properties for a wide range of industrial applications commercially.

We started to use the electron beam for ultra-clean vapor deposition of very small amounts of numerous materials in 1990. Our ultra-high-vacuum electron beam evaporator is today a standard tool in nanoscience laboratories . We will show how it works together with some application examples.

A growing request for new joining methods applicable to micro technology did encourage us to develop a dedicated micro-electron beam welder during the last years. We ended up with a desktop-sized instrument looking more similar to an electron microscope than to a common e-beam welder. This is not only a formal difference. Its design philosophy follows a number of technical solutions what are commonly used for scanning electron microscopes. Based on a long-erm experience on the field of electron optics, it is suitable to match the needs of a wide range of challenging joining tasks: from micro-mechanical and microsystem technological ones to a lot of precision technological applications, how they are common nowadays e.g. for medical technology or sensor industry. We will present some examples and will give a brief outlook in terms of the challenges of the future in this field.

10:50-11:10 AM
Prediction and Control of Distortion and Residual Stresses in Electron Beam Welding
Nick Bagshaw and Chris Punshon TWI Ltd.

Electron beam welding is recognized as an attractive method for minimizing distortion during welding, and is used frequently to join parts which are already finally machined or close to finished size. In such cases, before EB welding, it is of great value to be able to estimate the level of accuracy that will be achieved and the dimensional stability of the assembly throughout its service life. This presentation describes the development of a finite element (FE) modeling technique, validated by experiment, for predicting and understanding the development of residual stresses and distortion during EB welding, particularly in circular components. The use of this method for optimization of welding procedures  and residual stress mitigation methods is described and illustrated through a number of practical examples.

11:10-11:30 AM
Development of Local Vacuum Electron Beam Welding for Rapid Fabrication of Large Structures
Chris Punshon TWI Ltd.

Electron beam welding is generally carried out in a vacuum chamber, which is an attractive process characteristic offering many advantages in terms of containment, avoidance of contamination, and minimal metallurgical disturbance. To date, however, the necessity to conduct processing in a high vacuum atmosphere has largely restricted the application of the process to components and structures that can be entirely contained within a vacuum chamber.

This paper describes the innovative development of systems allowing the generation of high-power electron beams for use at  "reduced pressure"(~1 mbar), uniquely combined with developments in mobile, local seals. The requirements for sealing and pumping at this pressure are much less onerous than with high-vacuum EBW, thus facilitating the application of the process to much larger structures and components. A number of practical examples are described of how these process developments have been used successfully, illustrating the potential for application in a range of industry sectors and materials.

11:30-11:50 AM
Developments in Sub-10kW Electron Beam Equipment, Processes and Monitoring
Bruce Dance, TWI Ltd

When first developed, electron beam process equipment was limited in beam power. Developments in equipment mean that processing is now possible over a huge range of beam powers and qualities. However, despite the possibilities of higher beam powers, a huge amount of commercial EB processing is still carried out at low powers (<10kW).  In addition, although benefitting from modern control systems, the majority of EB process hardware still uses electron gun generator designs that are apparently little changed in the last 20 years, in stark contrast to laser equipments.

This paper reviews electron beam generator performance in relation to common process requirements, as well as the demands of more recently developed EB processes.  Beam probing and measurement data are presented.  Examples are given in which processes that demand specific beam qualities have been made possible by improved beam generation and control.

11:50 AM-12:10 PM
Investigations Relating to Electron Beam Welding of Dissimilar Metal Welds Based on Cast Iron
Karsten Rüthrich, TU Bergakademie Freiberg, Germany; Martina Mangler, TU Bergakademie Freiberg, Germany; Rolf Zenker, Zenker Consult Mittweida, Germany   

The combination of casting and welding in hybrid designs is a very interesting direction of development, especially in the automotive industry. Cast iron materials are either not weldable at all or weldable only with large-scale additional technological measures (pre-heating, post-heating, filler material).

Electron beams are characterized by good deflectability, thus making it possible to realize multi-spot and/or multi-process technologies. This means that different processes influencing the thermal regimes in the welding zone may be carried out in one processing step. 

First will be presented what EB multi-spot techniques and multi-process technologies mean and which opportunities are provided by them in connection with welding.

Furthermore, results of investigations relating to multi-spot welding of dissimilar metal welds based on cast iron (same-type, related-type) and unrelated-type welds of cast iron with steel will be presented. In addition, actual results of welding obtained using multi-process technologies (pre- and/or post-heating) in one processing step will be presented.

12:10-1:10 PM
Lunch
Hosted by AWS C7B Committee

1:10-1:30 PM
Joint Tracking with the Electron Beam Offline and Online – An Important Welding Automation Tool
Dr. Michael Mücke, Carsten Scheiblich, All Welding Technologies AG (Germany)

The electron beam is used in electron microscopy to image the smallest of structures.  Highly dependent on surface structure, it capitalizes on the angle of backscatter from electrons reflected off the target material.  This process is often used for imaging purposes in electron beam welding systems.  The viewing advantages over photo-optical methods such as telescopes or CCD cameras include a markedly superior depth of field and elimination of the need to illuminate the target surface.  The quality of these images has sufficient resolution for viewing typical joint forms.

The electron beam in EB welding systems is already being employed to identify joints for some welding projects. This process does not require a complete image of the surface.  The signal provided by backscattered electrons from a single deflection line perpendicular to the joint is sufficient.  The position of the joint can be ascertained by a change in the signal that occurs when the beam is reflected differently off the joint.

This process is customarily used to statically determine the joint position on one or a few points before the welding begins.  Errors in the positioning of the target piece are measured and the welding process is adjusted accordingly.  Even small tolerances in the assembly of a target piece can be offset.  Other processes use a search beam to probe multiple points along the entire course of the joint before welding begins (offline).  Measurable deviations from the reference position are saved and corrected during the welding process.  In so doing, even residual magnetic fields in the target piece or clamping fixture can be compensated for.

Deflection technology in electron beam welding system hardware and software has seen significant improvements during the past several years.  Using deflection frequencies as high as 200 kHz, it is now possible to conduct joint tracking during the welding process (online).  The electron beam periodically springs out of the weld pool to perform a nearly continuous scan perpendicular to the weld.  It moves far enough forward to take measurements ahead of the melt zone.  If the weld focus is not on the surface of the target piece, the focus position is switched to joint identification in order to receive a clear surface joint signal.  While the beam continues to weld after rebounding into the weld pool, the CPU calculates the deviation from the programmed reference position and corrects the weld position by deflecting the electron beam.

Examples will be used to illustrate the individual processes.  The results document the current state of this technology.  A view of prospective opportunities in electron beam process automation will be provided.

1:30-1:50 PM     
Fast Beam Deflection and Beam Quality– Keys to Economic High Quality Electron Beam Applications
Uwe Clauß, pro-beam AG & Co. KGaA (Germany)

Since its first introduction to the industry the control systems of electron beam machines have gone through an enormous development. With the availability of fast amplifier components and digital beam controllers, the advantages of the electron beam have further increased, making it a truly software-controlled thermal processing tool.

Modern beam controllers enable multi-beam and multi-focus technologies, where the beam is split in up to 60 or more individual beams. These technologies can reduce the processing time by parallel processing or improve the quality by optimized thermal expansion of the part. Multi-process technologies, where several processes are performed in one run (e.g. welding and cosmetic treatment), further extend the application range of the electron beam process.

Fast beam deflection in conjunction with electron-optical monitoring is the fundamental component for advanced seam tracking systems. They allow automating the EB application in order to optimize the process costs and improve the quality of the results in a reproducible manner.

Basis for a high quality of the EB process is the condition of the tool the electron beam itself. By introducing the beam parameter product to the electron beam, reliable information about the quality of the beam can be derived. Implemented into automatic beam alignment systems, repeatable results with high quality can be achieved.

1:50-2:00 PM
Break

2:00-2:20 PM 
Reconstitution of Fracture Mechanics Test Specimens by Electron Beam Welding
Peter Petrov, Institute of Electronics

Changes in the material properties due to neutron irradiation are monitored by means of surveillance programs. Specimensurveillance programs for reactor pressure vessel (RPV) materials are among the most important parts of inspection programms that are necessary for realistic evaluation of RPV lifetime.

In nuclear power plants (NPP), Charpy - Cv specimens are used to assess the RPV embrittlement. The surveillance capsule assemblies in each capsule contain typically 12 Cv and 3 tensile specimens. However, to address future plant life management, especially for older NPP's, it is necessary to obtain more statistics on the pressure vessel embrittlement. Reconstitution technology allows performing additional Cv or fracture toughness tests on a limited amount of available material and can contribute to a better characterization of the material and, therefore, to a better evaluation of the embrittlement degree of RPV steel due to neutron irradiation.

This presentation reports results from reconstitution of Cv-type and CT specimens by electron beam welding. The experiments were carried out using a 15 kW Leybold Heraeus welding unit. The material used in this study is 18MND5 steel. Investigations were made of structural changes of metal in welds and heat-affected zones. Cv impact tests showed good agreement between the original and reconstituted specimens.

2:20-2:40 PM 
Non-Vacuum Electron Beam Cutting
N. Murray, A. Beniach, R. Konya, Dr. Th. Hassel, Prof. Dr-Ing. Fr.-W. Bach, Institut für Werkstoffkunde (Germany)

The main domain of non-vacuum electron beam (NVEB) technology has so far been high-speed and high-quality joining. It is of great interest to find further uses for this efficient technology. Current research by the NVEB-group of the Institute of Material Science at the Leibniz University of Hannover focuses on the implementation of the NVEB process to the cutting of metal plates. Experiments are conducted on a PTR NVEB welding system with an acceleration voltage of 175 kV and a maximum power of 25 kW. First experiments with this equipment showed that it is possible to cut 20-mm-thick plates of mild steel. A cutting speed of 1 m/min at a beam current of 140 mA was achieved. Despite the well-known widening of the electron beam due to the scattering of the electrons in atmosphere, the resulting face is straight and of high quality, with only little residual melt drops at the lower edge. At the moment, preparations are being done to use a gas jet to blow away molten material from the cutting area to further improve surface finish of the cut. To evaluate the possibilities of expanding the work domain of the NVEB, process experiments will be done using the electron beam for weld preparation and welding within two steps on the same equipment.

2:40-3:00 PM
Modeling of Heat Transfer and Fluid Flow during Keyhole Mode Electron Beam Welding
R. Rai, T.A. Palmer, J.W. Elmer*, and T. DebRoy, Department of Materials Science and Engineering, Pennsylvania State University; *Lawrence Livermore National Laboratory, Livermore (USA)

A three-dimensional numerical model of the turbulent heat transfer and fluid flow in keyhole-mode electron beam welding has been developed and validated.  In addition to solving for the enhanced heat and mass transport due to turbulence, this model also considers the heat balance at the keyhole walls and the variation of vapor pressure in the keyhole and the keyhole wall temperature with depth.  Since the model takes into account these various physical processes, it can be applied to materials with different thermo-physical properties.  In this work, the model was validated using several 304L stainless steel welds made at fixed input power but different power densities achieved by variation in the focal spot size, and the calculated and experimental weld geometries were in reasonable agreement.  Peclet number calculations show that convective heat transfer is very significant, and computations performed in the presence and absence of convection also demonstrate the important role of convection on the formation of the resulting weld geometry.

3:00– 3:20 PM 
Welding of an Anaesthesia Tank of Aluminum Die Casting with Multi-Jet Electron Beam
O.Krahn, H. Pries, K. Dilger, Institute of Joining- and Welding-Technology of the Technical University (Germany)

The process of aluminum die casting, which produces near-net-shape, complex, and thin-walled prefabricated parts of aluminum, finds more and more applications in all areas of the industry because it has economic advantages compared to other processes in productivity. The technically most-used molding process of aluminum die casting products is fusion welding, which shows multiple problems. The safe production of pore-free welding seams requires an expensive optimization all over the die casting process as well as the choice of a qualified welding process.

An innovative approach to solve these problems is the integration of the electron multi-jet beam welding in the manufacturing chain.

To avoid distortion at small welding seams, high-frequency deflection of the electron beam is used, to connect the welded joint and the local successive fusing in one process step to reduce the porosity. This aided project shows successfully that it is possible to qualify the welding of an anaesthesia tank in normal die casting quality with the electron multi-jet beam as an economic and applicable operation of mass production for premium, pressure-tight units.

It was shown that an optimization of the welding parameter and the welding sequence over the multijet electron beam can reduce the porosity of the welding seam under 8%. That puts us in a position to fulfill the technical requirements for medical products.

3:20– 3:40 PM
Micro Electron Beam Welding of Metal Foils and Wires
Backhaus, Dorfmüller, Dr. Olschok, Prof. Dr.-Ing. Reisgen, ISF - Welding and Joining Institute, RWTH Aachen University


3:40– 4:15 PM
The Electron Beam as Versatile Tool for the MEMS and Precision Engineering Technology
Dr.-Ing. Klaus Dilger, Universitätsprofessor, Materialprüfstelle für Schweißtechnik und Werkstoffe
Dr.-Ing. Prof. h.c. Stefan Böhm, Professor, Fachgebiet Mikrofügen

Under the framework of a public sponsored project, an electron beam -based production line for micro systems was developed and built. Different processes like structuring, joining, material removal, measuring and visualization can be performed in one installation without tool changes in a precise and flexible manner.

The electron beam is not only providing the machining capabilities, but also the opportunity to observe the work piece and production steps by the use of backscattered electrons, presenting a flexible tool for quality assurance.

In the last years, detailed studies about micromachining processes using an electron beam were performed on different types of machines, like a scanning electron microscope or conventional electron beam welding machines. But in comparison to this attempts our built micro-electron beam machine is much more stable, more precise, the power is between 1 watt and 500 watts and the beam diameter less than 50 microns.

The latest results of the machine development and the experiments will be presented.

4:15-5:00PM
AWS Show

Wednesday, November 18
Session 3: Application Trends

9:00-9:45 AM
Keynote Asia: Asia Business Developments
Electron Beam Welding in Japan
Hirosada Irie, The Japan Welding Technology Center

Since the 1970s, considerable researchand development in the electron beam welding technology have been carried out in Japan. Owing to the long-term recession of the Japanese economy since the 1990’s collapse of the bubble and the R&D activities of new technologies -- laser technology, FSW -- the R&D activities in electron beam welding technology have scarcely been published.  However EBW technology has walked with steady steps in industries.  As well known, the feature of EBW is deep penetration and low distortion.  Since the bubble collapse, usage of EBW in Japan completely divided two extreme fields; that is, one is the construction of heavy gauge facilities and the other in mass production of small automotive and machine parts.  The shipment of EB welders for the latter applications has been still active.  In big construction, recently, the development of EBW of high-pressure gas pipe and the development of the welding process of overpack (container) for high level radioactive waste, and others, have been carried out.  A brief introduction of electron beam welding technologies in Japan will be presented.

9:45-10:15 AM  
Keynote America: America Business Developments
Don Powers, Retired, PTR-Precision Technologies, Inc.

10:15-10:40 AM
Break

10:40-11:00 AM  
Fabrication and Closure Welding of Containers for Long Term Storage of High Level Nuclear Waste Using Reduced Pressure Electron Beam Welding
Jim Dorsch, Ed Savage, Chris Punshon and Nick Bagshaw, TWI Ltd.

The growing demand for new base-load electricity generation will see an expanding role for nuclear energy as a major component. In consequence, increasing demands will be placed on the safe treatment and storage of high level nuclear waste (HLW). The current proposal for the USA is currently under review, but it is likely that spent fuel will be stored in a geological repository for a period of the order of a million years. The use of multiple-barriers to safely isolate HLW has been proposed, and the use of welding for fabrication and final closure of the containers considered. This paper describes a program of work carried out to examine the potential benefits of employing local vacuum, reduced pressure EB welding for both fabrication and sealing of containers for HLW, taking into account the demanding requirements for reliability, productivity, and concerns related to welding-induced distortion and residual stress.

11:00-11:20 AM 
EB Surface Engineering for High Performance Heat Exchangers
A. L. Buxton, TWI Ltd; R. J. McGlen, Thermacore Europe Ltd.

From aircraft engines to electronic devices, current thermal management systems are limiting product performance. Heat exchanger designs have been constrained by the available production technologies, eg. machining or chemical etching, but a newly developed electron beam manufacturing process (Surfi-Sculpt) offers the potential to bring about a step-change in heat exchanger efficiency.

An electron beam in conjunction with a sophisticated beam deflection system is used to move material around the surface in a controlled manner to rapidly create a wide variety of complex surface structures, many of which are impossible to produce via any other processing route. New heat exchange surfaces and structures have been modelled to understand how different designs of surface feature can influence the flow behavior over a surface, and a parallel set of wind tunnel tests have been used to verify results. Ultimately this will enable the optimization of surface geometries for heat transfer and allow revolutionary changes in heat exchanger design.

This paper describes the background and scope of a new electron beam manufacturing process. The results of both modeling and wind tunnel testing are presented to demonstrate the impact of this technology on heat exchanger design and efficiency.

11:20-11:40 AM
The Use of Filler Metal Shims to Improve Electron Beam Weldability
Daniel Nowak, GE Energy; Gary LaFlamme and John Rugh, PTR-Precision Technologies, Inc.

Electron beam welding is normally considered an autogenous welding process and is typically used to join components with tight-fitting faying surfaces.  Welding autogenously using the electron beam is ideal for producing the lowest possible heat input and minimal distortion by virtue of the processes narrow fusion zone.  However, there are materials that cannot be fusion welded autogenously, such as 6000 series aluminum alloys.  In these cases, a filler material must be used to change the weld metal chemistry to prevent cracking.  The normal method for adding filler metal in conventional arc welding processes is to feed wire into the molten weld pool.  This wire feeding method is suitable for the relatively shallow and wide welds produced by conventional non-keyhole welding processes, but it does not provide an adequate distribution of filler metal in the narrow, deep, rapidly solidifying welds produced by the EB welding process.  To overcome this lack of filler metal distribution problem, it is possible to pre-place shim material between the faying surfaces prior to welding.  This provides an even distribution of filler throughout the depth of the weld.  However, the electron beam profile needs to be modified to accommodate the wider fusion zone and some of the inconsistencies of a shimmed joint.

This paper presents the use of filler shims in a number of applications in aluminum alloys and 300 series stainless steel.  Properties data are also presented for select applications.

11:40 AM-12:00 PM
Electron-Beam Welding for Big Science
Dr.-Ing. Wilfried Behr, Zentralabteilung Technologie (ZAT)

The ISF (Institut for Welding Engineering and Joining Technology) at the RWTH Aachen (Aachen University) and the ZAT (Central Department of Technology) at the Forschungszentrum Jülich have worked for decades successfully in the development and application research of the joining technology. The FEZ (Excellency Center for Joining Technology) connects the technical authority of the RWTH Aachen and the Forschungszentrum Jülich. The combined use of personnel and machine resources offers a complete joining technology specialized authority unique in Europe. Both for the industrial site in Germany and in the global competition of the engineer-scientific research, this is  very useful, since the FEZ can solve questions made of industry and research as a competent development partner.

The ZAT in the Forschungszentrum Jülich transfers the tasks of the non-university research, development and manufacturing for research establishments and major items of scientific equipment cooperating world-wide in the FEZ. Current joining tasks e.g. for the international fusion experiment ITER in Cadarache/F, for the Spallation Neutron Source SNS in Oak Ridge/USA, for the research reactor FRM II in München/D and for FAIR (Facility for antiproton and ion Research) experiment in Darmstadt/D. The section “beam welding technology” of the ZAT can offer the necessary machine equipment and specialized authority to the research partners with its decades of experience in the processing of special metals as ideal development partner. Embedded into the range special joining and inspection technique can the ZAT a comprehensive research and manufacturing service offer, which are necessary to the solution of more complex joining and technical questions. Electron-beam welding is frequent with the solution of these joining technology questions of central importance. Only with the unique characteristics of this process, the almost boundless deflection technology, the outstanding protection of the melt against atmospheric influences by the vacuum and the highly precise power control material can be worked on such as niobium, molybdenum and titanium in addition, copper and aluminium in the necessary quality.

12:00 PM-1:20 PM
Lunch
Hosted by AWS C7B Committee

1:20-1:40 PM   
Electron Beam Welding of Aluminum Alloys for the Automotive and Aircraft Industry
Prof. Dr.-Ing. Stefan Böhm, Christian Börner, Kai Noack, Prof. Dr.-Ing. Klaus Dilger, Institute of Joining and Welding Technique, Technische Universität Braunschweig (Germany)

In an actual project sponsored by the EU, the electron beam is used for the welding of ductile aluminum die cast alloys for crash-optimized lightweight components for the automotive industry and aluminum wrought alloys for helium-proof chassis of aeronautic and aerospace instruments. For welding of ductile aluminum alloys, the challenges are the mechanic-technological joint properties, because ductile aluminum die cast is difficult to cast and so the hydrogen induced porosity is high. For welding of chassis made of aluminum wrought alloys, the shape of the chassis are not symmetrical rotationally, but complicated. The components are made by precision-casting. Here the heat transfer into the material, the welding order, and the start and stop craters are the challenge.

The paper will show how modern electron beam technology is able to fulfill the requirements of the welding tasks using multiple beams and multiple focuses.

1:40-2:00 PM   
Applications of Electron Beam Diagnostics in Characterizing Low and High Voltage Electron Beam Welders
K.W. Lachenberg, T.A. Palmer**, A.T. Teruya*, and J.W. Elmer*, Sciaky Inc., * Lawrence Livermore National Laboratory; **Applied Research Laboratory, Pennsylvania State University (USA)

Over the past two decades, the development of diagnostic tools for characterizing electron beams has been growing in prominence.  The Enhanced Modified Faraday Cup (EMFC), developed at Lawrence Livermore National Laboratory (LLNL), provides measurements of the general size and shape of the beam and the power density distribution across its width.  This tool has been utilized in a number of common applications, including the characterization of machine performance for high- and low-voltage electron beam welders, the transfer of parameters between welders at remote locations, and as a process control tool.  Because of its capability to quantify beam characteristics, the EMFC can also prove to be a useful tool in diagnosing differences in machine performance related to differences in machine construction.  By employing the EMFC diagnostic tool, the power density distribution of the beam from a given electron beam gun configuration can be determined.  This quantitative information can then be used as a baseline for providing a better understanding of how different features of the electron gun or power supply affect the resulting beam power.  The use of the diagnostic tool will provide a better understanding of the operation of these machines and prove instrumental in producing improved designs for the next generation of electron beam guns and power supplies without extensive visual and destructive testing. 

2:00-2:20 PM
Break

2:20-2:40 PM
Electron Beam Welding – Process, Applications, Equipment and Future Developments
Dr. Schubert, G.  PTR-Precision Technologies, Inc. (USA)

This presentation gives a technical overview of unique features of the electron beam welding process. Applications from different types of industries and different materials will be discussed and technical challenges will be highlighted, as well as how they can be solved with the EB process. Weld cross sections of production parts will be shown to demonstrate weld shapes obtainable. In addition, an overview of today’s welding equipment will be provided, ranging from universal chamber welders to flexible and dedicated production welders with short cycle times. Integration of high production welders into fully automated production lines will also be reviewed. A brief outlook will be given into future developments.

2:40- 3:00 PM  
New Capabilities for Efficient Application of Electron Beam Welding for the Fabrication of Large-Scale Parts in Series Production
Volker Adam, pro-beam AG & Co. KgaA (Germany)

One domain of the electron beam is the possibility to join finished or near-net-shape machined parts distortion-minimized. This technology was field-tested and applied for more then 50 years for safety-related parts in space, aviation, military and nuclear applications. Simultaneously the technique is predestined for deep penetration welding of wall thicknesses up to 100mm and more. Possibilities in this field have been discussed in the past, but so far, hardly any equipment was available for flexible and economic operations.

Machines and control systems have been continuously developed by pro-beam. As a result, fast and economic machines with chamber volumes up to 600 m³ for welding of large-scale parts with weights above 50 tons are available. 

Enormously increasing or fluctuating commodity prices, especially for high-alloyed steels and noble metals ,force up the importance of EB-welding in vacuum without filler material. The low energy consumption of modern EB systems, the matured technology, and the high availability of the systems have turned the technology into an economic production method for semi-finished products.

Large-volume cast or forged parts, as well as large-sized sheets can be subdivided into smaller components, faster and better available, and joined economically with high-quality by EB in the vacuum.  New applications in the areas of shipbuilding, aviation and offshore wind power as well as for system and machine building are in pre-series or series production.

The paper reflects the current status of the production and will give future prospects of EB welding in the area of large-scale parts. Besides technical aspects, in particular, economic aspects are discussed.

3:00- 3:20 PM  
Studies on the Electron Beam Welding Behavior of Different Lightweight Materials
Marco Klemm, SZF Stahlzentrum and Rolf Zenker, TU Bergakademie

For modern lightweight design, it is becoming more and more necessary to produce welding constructions of lightweight materials as well as same-type design and also multi-material design. This makes high demands on the welding technologies itself, but also on additional thermal pre- and post-processes
in connection with the welding process.

The electron beam (EB) can meet the requirements for realizing such complex welding tasks. By using high-frequency beam deflection, it is possible to realize multi-spot welding and/or multi-process technologies in connection with welding.

The paper deals with results relating to EB welding of several Al and Mg alloys and different combinations of these materials. EB welding was realized without filler materials to connect components up to 25 mm in
thickness.

The quality of the weld (porosity, sensitivity to cracking), the microstructure and hardness of the welding seam, and the HAZ and the tensile behavior in comparison to the base materials were investigated.

Same-type and related-type welds of lightweight joints have a good quality and mostly very good properties. In case of unrelated-type welds, the welding results depend on the kinds of welding partners used.

3:20- 3:40 PM
Electron Beam Weldability of Aluminum-Based Dissimilar Alloy Joints
Michinori OKUBO, Toshiyuki HASEGAWA, Nihon University, Japan; Nobuyuki ABE, Osaka University, Japan

Aluminum alloy joints of dissimilar composition will give problems due to difference properties. The electron beam machine is 6 kW for high voltage type. Joint configuration is I type and without filler metal. Electron beam welds are produced on dissimilar aluminum alloys of 10 mm in thickness.

Al-Si alloy shave good performance. Main aluminum alloy is extruded Al-Si plate. Combination wrought alloys are Al-Mg, Al-Mg-Si and Al-Zn-Cu alloy plates. Hardness of Al-Si/Al-Mg and Al-Si/Al-Mg-Si weld metals is same level as both alloys. Tensile strength becomes about 200MPa. In case of Al-Si/Al-Zn-Cu joint, joint elongation is the lowest shown, and they are 80% of the base metal. Impact value shows a tendency to decrease. Micro-segregation of Mg, Si and Cu in weld metals is recognized for Al-Si/Al-Mg-Si joint.

Nanostructure aluminum alloy have high strength and good performance. The main alloy is nanostructure aluminum alloy. Combination aluminum-based alloys were extruded Al-Si plate and wrought Al-Mg, Al-Mg-Si and Al-Zn-Cu alloy plates. Dissimilar welding for nanostructure aluminum alloy to various aluminum-based alloys by electron beam welding process can be possible and crack-free. But some porosity is recognized in weld metal. As for hardness of the weld metal, they become 107 to 124HV with each joints. The high energy density processes such as electron beam welding are suitable because the heat-affected zone width is very narrow.

3:40-4:00 PM
Panel Discussions

4:00-5:00 PM
AWS Show

• Basics of beam generation  (beam source, influence of high voltage and magnetic fields, vacuum, deep penetration welding effect)
• Rules for design (theory and practical examples, EB conform design, parts preparation)
• Weldability of metallic materials (rules and practical applications)
• The multifunctional EB (quality assurance, seam tracking, online process control, automatic beam adjustment, multi-spot and multiprocess technologies)
• EB machines (single machines, production cells, EB welding of large parts, product life cycle)
• Criteria for EBW applications (examples for industrial applications)

Questions, to register or need additional conference information? Call
(800) 443-9353 x 455 (U.S.) or
(305) 443-9353 x 455 (outside the U.S.)

Register online or via mail/fax form here.