This work presents the results of an investigation into the influence of beam offset on the structure and mechanical properties of electron-beam-welded joints between Ti6Al4V and Al6082-T6 alloys. The experimental procedure involved the use of specific technological conditions: an accelerating voltage of 60 kV, an electron beam current of 35 mA, a specimen motion speed of 10 mm/s, and a beam offset of 0.5 mm towards both alloys, as well as welding without an offset. The phase composition of the joints was analyzed using X-ray diffraction (XRD). The microstructure and chemical composition of the seams were studied by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The results obtained for the structure of the joints show that the beam offset has a significant influence on the structure. The microhardness was studied by means of the Vickers method. The results for the microstructure showed that the welding procedure without offset and with an offset towards the Ti alloy leads to inhomogeneous welded joints with a significant amount of intermetallics. The offset towards the Al alloy leads to the formation of a narrow area of TiAl₃ phase. The measured microhardness corresponds to the increased amount of intermetallics in the case of offset towards the Ti alloy, with which the highest values were presented (about 58% higher than with Ti6Al4V plate). The results obtained for tensile properties show that the offset to the Al6082-T6 alloy leads to the highest values of tensile strength (TS) and yield strength (YS), which are twice higher than in welding without offsetting of the electron beam.

In this study, we present the results of electron-beam welding of joints with 304-L stainless steel and copper. The influence of the beam’s power on the structures and mechanical properties of the welded joints was studied; the experiments were realized at a beam deflection of 0.3 mm to the Cu plate and beam powers of 2400, 3000, and 3600 W. The phase compositions of the obtained welded joints were studied by using X-ray diffraction (XRD); the microstructure and chemical composition were investigated by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX), respectively. The mechanical properties were studied by using tensile experiments and microhardness investigations. The phase compositions of the welded joints were in the forms of substitutional solid solutions between Fe, Cu, and pure copper and remained unchanged in terms of power. It was found that the microstructures changed gradually with the application of different values of the power of the electron beam. The results of the tensile tests showed higher tensile strengths at lower beam powers (i.e., 2400 and 3000 W) that dropped at 3600 W. The relative elongations rose with increases in the power of the electron beam. Moreover, it was found that the microhardnesses strongly depended on the applied technological conditions (defined by the electron beam’s power) and the corresponding microstructures of the welded joints.

This article presents the effects of novel electron beam hardening (EBH) process parameters in terms of residual stresses (RSs) and microstructure modification in as-received C45 cylindrical specimens. The EBH was performed using continuous irradiation with power in the range of $720–2070\mathrm{W}$ on an Evobeam µEBW Cube 400 machine. A distinctive feature of the novel surface hardening process is the linear scanning mode in the axial direction of the treated cylindrical surface, which makes it suitable for machining shafts and axles. Using a one-factor-at-a-time technique, the individual effects of the electron beam current ${\mathrm{I}}_{\mathrm{b}}$, workpiece peripheral velocity ${\mathrm{v}}_{\mathrm{p}}$, scanning frequency (SF), and focal length (FL) on the RSs and microstructure in surface layers were evaluated. The X-ray diffraction results, scanning electron microscopy (SEM) images, and phase analyses confirmed the significant potential of the EBH process for forming compressive RSs due to martensitic transformation in the surface zone and gradient microstructure in terms of structure and phase composition. The measured maximum compressive axial and hoop RSs of $-289.5$ and $-345\mathrm{M}\mathrm{P}\mathrm{a}$, respectively, and compressive zone at a depth of approximately 0.3 mm correlate with the phase transformation region at a depth of approximately 0.2 mm. Based on the results for RSs and microstructure modification, the limitations with respect to the suitable operating parameter values were established. After excluding these operating parameter values, the following suitable ranges of the operating parameters were determined: ${\mathrm{I}}_{\mathrm{b}}\in \left(16,36\right)\mathrm{m}\mathrm{A},{\mathrm{v}}_{\mathrm{p}}\in \left(18,45\right)\mathrm{m}\mathrm{m}/\mathrm{s}$, $\mathrm{S}\mathrm{F}\in (5000,\mathrm{20,000})\mathrm{H}\mathrm{z}$, and $\mathrm{F}\mathrm{L}\in (+5,-5)\mathrm{m}\mathrm{m}$. The specified ranges are the basis for conducting a planned experiment on the novel EBH process.

In the present work, the influence of a magnetron-sputtered copper interlayer on the process of electron beam welding of Ti6Al4V and Al6082-T6 plates was investigated. A sample without a filler was also prepared as a control. The microstructure, microhardness, and tensile properties of both samples were determined. Applying a copper interlayer resulted in the formation of an additional CuAl₂ intermetallic compound in the form of a eutectic structure along the boundary of the aluminum crystal grains. A noticeable shift in the preferred crystallographic orientation of the aluminum phase from the denser {111} family of crystallographic planes in the case of the sample prepared without a filler towards less-dense ones such as {110}, {100}, and {311} in the case of applying a copper filler was observed. This was most probably caused by the lower free surface energy of the crystals oriented towards the {111} family of crystal planes, which favored the chemical bonding between the aluminum solid solution and the CuAl₂ intermetallics. As a result of applying the copper interlayer, a noticeable increase in the microhardness of the weld seam was observed from 78 ± 2 HV0.05 to 136 ± 3 HV0.05. Applying a copper interlayer also led to an improved energy absorption capacity of the weld seam, as suggested by the increase in the UTS/YS ratio from 1.03 to 1.44. This could be explained by the smooth transition between the highly dissimilar Ti6Al4V and Al6082-T6 alloys. The UTS of the sample with the copper filler reached 208 MPa, which was about 60% of that of the base Al6082-T6 alloy.

The aim of this study is to determine the weldability of different materials - AISI 316L stainless steel and carbidic austempered ductile iron (CADI) by electron beam welding (EBW). Welding is performed with different beam current (Ib) of 10 mA and 20 mA, welding speed (V) of 400 mm/min and 1000 mm/min with an offset relative to the stainless steel of 0.2 mm at a constant frequency deviation (Freq). Vickers microhardness is measured in the fusion zone (FZ) and in the heat affected zones (HAZ). The most suitable welding mode is determined in terms of higher microhardness in the FZ with the presence of defects in the weld seam.

The present study is related to the implementation of Electron Beam Welding of 316L stainless steel blanks obtained by traditional methods of plastic deformation and a blank made of LaserForm Maraging Steel obtained by Additive manufacturing also known as 3D Metal Printing Technology. A microstructural analysis was performed using a Scanning Electron Microscopy (SEM). To determine the chemical distribution at the fusion zone (FZ) an energy dispersive spectroscopy (EDS) was used. Vickers microhardness distribution across the welded seam was investigated in two zones – the first one at 1 mm from the surface and the second one at 3 mm from the surface.