Effect of the beam oscillation on the structure and mechanical properties of electron beam welded joints of Ti6Al4V and Al6082-T6 alloys

Abstract

The results of electron beam welding of Ti6Al4V and Al6082-T6 alloys are presented. The influence of electron-beam scanning geometry on the structure and mechanical properties of the welded joint is studied. Two kinds of samples were investigated – the first specimen was welded without beam oscillation and the second one was obtained using an oscillating electron beam following a circular trajectory of scanning with an oscillation radius of 0.2 mm. X-ray diffraction (XRD) method was used for the determination of the phase composition of the welded joints. The microstructure of the welded joints was studied using Scanning electron microscopy (SEM). Energy-dispersive X-ray spectroscopy (EDX) was applied for the chemical composition investigation. Tensile experiments and microhardness measurements were performed to study the mechanical properties of the welded joints. The sample welded without the application of an oscillating beam showed higher values for the yield strength and tensile strength. The values measured for the microhardness within the welded seam are about 450 HV0.05 in both cases. However, the application of a beam oscillation leads to a significant increase in the micro-hardness of the heat affected zone at the Ti-based alloy. The measured values reached 627 HV0.05.