Steel to aluminium braze welding by laser process with Al–12Si filler wire

Abstract

The joining of DC04 steel to 6016-T4 Al alloy is achieved by laser braze welding using a 4047 (Al12Si) filler wire and a brazing flux. The dissimilar joining is obtained both by welding the parent 6016 alloy to the 4047 filler wire, producing a continuous bonding without apparent macroscopic flaws, and by reactive wetting of the molten Al alloy on the solid steel, resulting in the formation of a thin layer of Fe-Al-Si intermetallic compounds at the steel/bead interface. The linear strength of the assemblies can be as high as 190 N mm 21 , with a failure generally located in the reaction layer of the steel/bead interface. Last, the strength of the assemblies is shown to increase linearly with the reaction layer width.

Intermetallics Synthesis in the Fe–Al System via Layer by Layer 3D Laser Cladding

“…Another interesting direction is the laser welding of dissimilar materials, i.e., Fe and Al alloys, which is important for the aerospace and automobile industries where serious difficulties are caused by the high brittleness of the intermetallide phases generated in the melting pool [26][27][28][29][30][31]. On knowing the succession of the phase-structural transformations in the laser weld joint, it is possible to attain the fabrication creation of such a barrier layer of the alloying elements [26,27,30], that is capable of wetting the joining alloys on the basis of iron and aluminum, which protects them from the contact during the melting and prevents the formation of undesirable phases.…”

Characterization of Intermetallic Compounds in Dissimilar Material Resistance Spot Welded Joint of High Strength Steel and Aluminum Alloy

“…The interaction between liquid aluminum alloy and solid steel induced the formation of Fe-Al intermetallic compound layer. 24,31,33) Figure 7 shows distributions of Fe and Al across the interface. It indicated that the growth of the intermetallic compounds was controlled by the reactive diffusion between the liquid aluminum alloy and the solid steel.…”

“…4,24) However, few publications concerning resistance spot welding of steel and aluminum alloy have been reported to date, and the limited studies focus on the use of transition materials such as aluminum clad steel plate to aid the resistance spot welding process. [26][27][28] Accordingly, there is a lack of understanding on resistance spot weldability of the dissimilar materials of steel and aluminum alloy.…”

“…15,16) The solid state welding techniques are expected to restrain the growth of the intermetallic compound layer within a permissible limit, which has been identified as 10 μm thickness, 17) but the adaptability of these methods is restricted in automotive industry due to equipment configuration. In the last few years, arc welding-brazing, [18][19][20][21] laser reactive wetting 6) and laser brazing 4,5,[22][23][24][25] of the dissimilar materials of steel and aluminum alloy have drawn great attentions. Lin et al [18][19][20] studied dissimilar metals TIG welding-brazing of aluminum alloy to stainless steel using Al-Si, Al-Cu and Al-Si-Cu filler wires.…”

Control of mass and heat transfer for steel/aluminium joining using Cold Metal Transfer process

“…10,11 The reactive-wetting or braze-welding technique in a lap-welding configuration specially gives promising results. [12][13][14] It consists in melting aluminium base metal or a low melting point aluminium filler metal, producing its spreading on the solid steel base metal. However, if the wetting of liquid aluminium is possible on zinc coated steels, it requires the use of a brazing flux on non coated steels.…”