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Methods of joining materials
Published in William Bolton, R.A. Higgins, Materials for Engineers and Technicians, 2020
When a stream of fast-moving electrons strikes a target, the kinetic energy of the electrons is converted into heat. Since the electron-beam can be focussed sharply to impinge at a point, intense heat is produced there. To be effective, the process must be carried out in a vacuum, otherwise electrons tend to collide with the molecules in the air between the electron gun and target and become scattered from their path. Consequently, electron-beam welding is at present used mainly for ‘difficult’ metals which melt at high temperatures, e.g. tungsten, molybdenum and tantalum, and also for the chemically reactive metals beryllium, zirconium and uranium, which benefit from being welded in a vacuum.
Solid Materials: Joining Processes
Published in Leo Alting, Geoffrey Boothroyd, Manufacturing Engineering Processes, 2020
Electron beam welding is defined as a metal joining process where melting is produced by the heat of a concentrated stream of high-velocity electrons. The kinetic energy of the electrons are changed into heat upon impact with the workpiece. Energy density at the work can amount to 5 × 1012 W/m2, a much higher figure than for any other arc welding process. In most applications no filler material is used.
Welding and Fabrication (including metallic surfacing)
Published in Harry J. Meigh, Cast and Wrought Aluminium Bronzes, 2018
Electron-beam welding consists in focusing a beam of high-velocity electrons on the weld area. The kinetic energy of the electrons is converted into heat energy which melts the metal. The process has to be carried out in a vacuum chamber since the presence of molecules from the air would interfere with the working of the electronbeam and would cause oxidation. No filler wire is needed.
The synergy between powder metallurgy processes and welding of metallic alloy: a review
Published in Powder Metallurgy, 2020
Ayorinde Tayo Olanipekun, Nthabiseng Beauty Maledi, Peter Madindwa Mashinini
Electron beam welding (EBW) method melts and joins metals by heating with electron beam. EBW is normally carried out in a high vacuum (). It has has the capability of giving a high cooling rate and high hardness in carbon steel. Also, EBW gives low distortion, keeping the dimensional stability of near net shape PM welded alloy [4,41]. Meanwhile, the metallic materials welded with an EBW method usually have a greater tendency for pore formation due to the vacuum acting as a potential site that trap gas during welding. However, choosing a suitable welding beam parameter has been known to control porosity in the sintered ferrous compacts [42].
Electron-beam welding of high-entropy alloy and stainless steel: microstructure and mechanical properties
Published in Materials and Manufacturing Processes, 2020
R. Sokkalingam, P. Mastanaiah, V. Muthupandi, K. Sivaprasad, K. G. Prashanth
Electron-beam welding (EBW) is one of the high-energy beam welding processes, which has the ability to produce high-quality clean weld joint with high joint efficiency (reliability). It makes the electron-beam welding (EBW) process suitable for fabricating joints with high precision in power plants, aerospace, and automobile sectors.[37] The key-hole characteristics make the process special by producing weld with high depth to width ratio, high depth of penetration, and minimum volume of weld fusion zone in the weld joint.[37] Furthermore, the electron-beam welding (EBW) process can minimize/mitigate the heat-affected zone (HAZ), and unmixed zone width and the joint distortion with minimal weld fusion zone volume, and with a minimum amount of defect formation[18,20,37–40] due to lower heat input and shorter retention time compared to the conventional arc welding processes. Also, the higher energy density in the electron-beam welding (EBW) process enables the fusion of two different abutting materials even if their melting point is too different.[41] The weld shape, size, and beam alignment can be controlled precisely depending on the manufacturer’s need.[41] This process characteristic makes the electron-beam welding (EBW) process as one of the ideal welding processes in the area of dissimilar welding, especially for components exposed to critical applications. Up to the knowledge of the authors, there are no published data available on the dissimilar electron-beam welding of high-entropy alloy with austenitic stainless steel. Hence, in order study effect of electron-beam welding (EBW) process on the microstructure and mechanical properties of Al0.1CoCrFeNi-high entropy alloy/austenitic stainless steel dissimilar joint and to mitigate/reduce the width of the heat-affected zone and unmixed zone, the present study deals with the fabrication of dissimilar weld joint between Al0.1CoCrFeNi-high entropy alloy and stainless steel (i.e., AISI 304) by electron-beam welding (EBW) process with lower heat input.