Effects of Beam Oscillation on Porosity and Intermetallic Compounds Formation of Electron Beam Welded DP600 Steel to Al-5754 Alloy Joints

摘要

The formation of different weld defects like porosity and intermetallic compound (IMCs) in dissimilar electron beam welded (EBW) joints between DP600 steel to Al-5754 alloy was studied. EBW was performed under three weld conditions i.e. without beam oscillation and with beam oscillation at two different beam oscillation diameters for selecting weld parameters to obtain best quality weld products. X-ray diffraction, scanning electron microscopy with energy dispersive spec-troscopy (EDS), micro hardness were performed to characterize pores and IMCs qualitatively. Three-dimensional (3D) X-ray computed tomography (XCT) was also used to visualize and quantify both the defects and their distribution in 3D space at different regions of the joint such as fusion and heat-affected zone. Sample characterization with different characterization techniques demonstrated that application of beam oscillation with optimum oscillation diameter (1 mm) produced the best quality joints by decreasing both the defects significantly. It was further confirmed that increasing oscillation diameter beyond its optimum value, deteriorated the weld quality noticeably.