Electron beam welding of aluminum alloy AlMg6 with a dynamically positioned electron beam

Application of Dynamic Beam Positioning for Creating Specified Structures and Properties of Welded Joints in Electron-Beam Welding

“…The results of experimental and calculation studies of the weld metal crystallization process in EBW (20Cr3MoWV steel) are presented in Figure 5, which also presents the weld macrostructure (a), the shape of a crystallizing part of the welding bath with crystallite axis projections (b), and the diagram of changes in the macrostructure shape and crystallization scheme (c). The shape and sizes of the crystallizing part were determined by the thermal model (1,2); the crystallite axis projections were determined by the equations (4,5); the diagrams of changes in macrostructure shape and crystallization scheme were based on the calculations of integral crystallization criteria (6)(7)(8)(9)(10)(11).…”

“…The distance between the electron beam exposure zones was to have one general fusion channel formed by the electron beam in the metal (the size of the oscillation path must be small enough so that the area of the beam impact is limited to one common penetration channel). The parameters of this trajectory of dynamic positioning of an electron beam were determined based on preliminary calculations using thermal models [5,6,9]. The following parameters were determined: electron beam power-4000 W, welding speed-5 mm/s, electron beam operation time in each zone-250 µs, and longitudinal oscillation frequency-1000 Hz.…”

“…An increase in heat input enlarges a soft interlayer in TEZ, which may disrupt rigid weld joints in the course of operation, especially under bending loads. Also, structural phase transformations taking place in the welding zone mainly depend on the temperature-time parameters: degree of heating, heat distribution, heating, and cooling rates [5][6][7][8][9].…”

“…It is possible to regulate thermal cycles in EBW in order to produce a specified structure of a welded joint though controlling the thermal power of an electron beam due to its dynamic positioning [5]. The application of beam sweep makes it possible to carry out multifocal and multi-beam welding when welding is performed simultaneously in several treated areas [6,7], as well as combine the welding process with local heating or subsequent heat treatment.…”

An Experimental Evaluation of Electron Beam Welded Thixoformed 7075 Aluminum Alloy Plate Material

“…In addition, it can be said that although aluminum 7075 alloy is prone to cracking, the EBW process did not pose any significant problems, and only few numbers of pores were formed in the FZ, as shown in Figure 4b. Possible reasons for the formation of these pores could be the high specific energy density and evaporation of metal that is associated with EBW and thermophysical features of aluminum, including its low melting point, high thermal conductivity, and surface oxide films, with high melting points [9,14,16]. Figure 4c,d show the weld area at different magnifications.…”