Effects of Laser Offset and Hybrid Welding on Microstructure and IMC in Fe–Al Dissimilar Welding

Abstract

Abstract:Welding between Fe and Al alloys is difficult because of a significant difference in thermal properties and poor mutual solid-state solubility. This affects the weld microstructure and causes the formation of brittle intermetallic compounds (IMCs). The present study aims to explore the weld microstructure and those compounds over two different technologies: the laser offset welding and the hybrid laser-MIG (Metal inert gas) welding. The former consists of focusing the laser beam on the top surface of one of the two plates at a certain distance (offset) from the interfaces. Such a method minimizes the interaction between elevated temperature liquid phases. The latter combines the laser with a MIG/MAG arc, which helps in bridging the gap and stabilizing the weld pool. AISI 316 stainless steel and AA5754 aluminum alloy were welded together in butt configuration. The microstructure was characterized and the microhardness was measured. The energy dispersive spectroscopy/X-ray Diffraction (EDS/XRD) analysis revealed the composition of the intermetallic compounds. Laser offset welding significantly reduced the content of cracks and promoted a narrower intermetallic layer.

Structure and Selected Properties of Arc Sprayed Coatings Containing In-Situ Fabricated Fe-Al Intermetallic Phases

“…Intermetallic phases from the Fe-Al system are attractive coating materials with characteristic properties, especially in comparison with conventional coating materials. Coatings that involve intermetallic phases are at present created via thermal spraying [1][2][3] as well as welding via different methods [4][5][6][7] out of prefabricated intermetallic phase powders. Reports in literature also describe the processes of in-situ manufacturing of intermetallic phases on a modified surface by the alloying of components [8][9][10][11][12][13].…”

Influence of Pin Length and Electrochemical Platings on the Mechanical Strength and Macroscopic Defect Formation in Stationary Shoulder Friction Stir Welding of Aluminium to Copper

“…Apart from that, the presence of electrical current and elevated operating temperatures (e.g., in batteries) leads to further phase growth [7] and possible deterioration of the electrical and mechanical properties [8]. The formation of the specific IMCs between Al-Cu is not directly comparable to, for example, the case of Fe-Al or Fe-Mg, but is indeed very similar [9][10][11]. The extension and the morphology of IMC depend on the diffusion of the elements to each other, the dilution, the maximum temperature and on the cooling regime.…”

Laser Welding

“…The present special issue on "Laser Welding" was a success with a total of 16 original research works published after peer-review. Different topics were discussed within this special issue: modelling and simulation of laser welding were presented in [1][2][3][4]; porosity control by means of high speed imaging and microscopy techniques was studied and discussed [5]; the effect of processing parameters on the microstructure and mechanical properties of laser-welded joints was evaluated for different metallic systems such as AZ31 alloy [6], steels [7][8][9][10], Ti-based alloys [11][12][13], and Al-based alloys [14]; and finally, dissimilar laser welding of aluminum to steel was presented [15,16].…”