Large spot laser assisted GMA brazing–fusion welding of aluminum alloy to galvanized steel

Abstract Through positioning the leading laser as an auxiliary role, and the trailing arc as the main heat source, aluminum alloy (Al) was joined to galvanized steel plate with lap joint. The brazed seam width w increased with the increasing of heat input. The appropriate laser-wire distance Dlw and defocusing distance df to obtain the good fusion weld appearance were 5 mm and +20 mm, respectively. The fracture position of tensile test sample was divided into brazed interface fracture (P   0.6 kW). The maximum tensile strength of dissimilar joint reached 75% of that of Al. The shear strength was mainly decided by heat input, and the brazed seam had the highest microhardness. Joining mechanism of this process was summarized into two factors: the effective function of laser and the metallurgical function of zinc. Compared to gas metal arc welding (GMAW), large spot laser assisted GMA process improved weld appearance and enhanced the process stability and its time-efficiency.

[1]  M. Gao,et al.  Interface properties and thermodynamic analysis of laser–arc hybrid welded Al/steel joint , 2013 .

[2]  William M. Steen,et al.  Arc augmented laser processing of materials , 1980 .

[3]  Masao Ushio,et al.  Dissimilar Metal Joining of Aluminum to Steel by MIG Arc Brazing Using Flux Cored Wire , 2003 .

[4]  Jiakun Liu,et al.  Microstructure characteristics and mechanical property of aluminum alloy/stainless steel lap joints fabricated by MIG welding–brazing process , 2011 .

[5]  Ming Gao,et al.  Process and joint characterizations of laser–MIG hybrid welding of AZ31 magnesium alloy , 2012 .

[6]  Xinjin Cao,et al.  Research and Progress in Laser Welding of Wrought Aluminum Alloys. II. Metallurgical Microstructures, Defects, and Mechanical Properties , 2003 .

[7]  C. Dong,et al.  Arc joining of aluminum alloy to stainless steel with flux-cored Zn-based filler metal , 2010 .

[8]  K. P. Rao,et al.  Study on laser welding-brazing of zinc coated steel to aluminum alloy with a zinc based filler , 2011 .

[9]  E. Schubert,et al.  Light-weight structures produced by laser beam joining for future applications in automobile and aerospace industry , 2001 .

[10]  Kazutoshi Nishimoto,et al.  アルミニウムろうによる接合性の基礎的検討 －レーザブレイジングによるアルミニウム合金と鉄鋼材料の異材接合 (第1報)－ , 2004 .

[11]  F. Vollertsen,et al.  Laser-Mig Hybrid Welding Of Aluminium To Steel — Effect Of Process Parameters On Joint Properties , 2012, Welding in the World.

[12]  C. Dong,et al.  Dissimilar metal joining of aluminum alloy to galvanized steel with Al–Si, Al–Cu, Al–Si–Cu and Zn–Al filler wires , 2012 .

[13]  Ming Gao,et al.  Effects of welding parameters on melting energy of CO2 laser–GMA hybrid welding , 2006 .

[14]  Jürgen Bruckner,et al.  Influence of Filler Composition on the Microstructure and Mechanical Properties of Steel—Aluminum Joints Produced by Metal Arc Joining , 2009 .

[15]  Peng He,et al.  Interfacial microstructure and mechanical properties of aluminium-zinc-coated steel joints made by a modified metal inert gas welding-brazing process , 2007 .

[16]  P. He,et al.  Interfacial phenomena of cold metal transfer (CMT) welding of zinc coated steel and wrought aluminium , 2008 .