According to the differences in melting point between aluminum alloy and steel, 6013-T4 aluminum alloy was joined to galvanized steel by large spot Nd：YAG laser ＋ MIG arc hybrid brazing-fusion welding with ER4043（A...According to the differences in melting point between aluminum alloy and steel, 6013-T4 aluminum alloy was joined to galvanized steel by large spot Nd：YAG laser ＋ MIG arc hybrid brazing-fusion welding with ER4043（AlSi5） filler wire. The microstructures and mechanical properties of the brazed-fusion welded joint were investigated. The joint is divided into two parts of fusion weld and brazed seam. There is a zinc-rich zone at fusion weld toe, which consists of α（Al）-Zn solid solution and Al-Zn eutectic. The brazed seam is the Fe-Al intermetallic compounds （IMCs） layer of 2-4μm in thickness, and the IMCs include FeAl2, Fe2Al5 and Fe4Al13. FeAl2 and Fe2Al5 are located in the compact reaction layer near the steel side, and Fe4Al13 with tongue shape or sawtooth shape grows towards the fusion weld. The tensile strength of the joint firstly increases and then decreases as the welding current and laser power increase, the highest tensile strength can be up to 247.3 MPa, and the fracture usually occurs at fusion zone of the fusion weld. The hardness is the highest at the brazed seam because of hard Fe-Al IMCs, and gradually decreases along the fusion weld and galvanized steel, respectively.展开更多
Laser-metal inert-gas(MIG)hybrid welding-brazing was applied to the butt joint of 6061-T6 aluminum alloy and 304 stainless steel.The microstructure and mechanical properties of the joint were studied.An excellent join...Laser-metal inert-gas(MIG)hybrid welding-brazing was applied to the butt joint of 6061-T6 aluminum alloy and 304 stainless steel.The microstructure and mechanical properties of the joint were studied.An excellent joint-section shape was achieved from good wettability on both sides of the stainless steel.Scanning electron microscopy,energy-dispersive spectroscopy and X-ray diffractometry indicated an intermetallic compound(IMC)layer at the 6061-T6/304 interface.The IMC thickness was controlled to be^2μm,which was attributed to the advantage of the laser-MIG hybrid method.Fe3Al dominated in the IMC layer at the interface between the stainless steel and the back reinforcement.The IMC layer in the remaining regions consisted mainly of Fe4Al13.A thinner IMC layer and better wettability on both sides of the stainless steel were obtained,because of the optimized energy distribution from a combination of a laser beam with a MIG arc.The average tensile strength of the joint with reinforcement using laser-MIG hybrid process was improved to be 174 MPa(60%of the 6061-T6 tensile strength),which was significantly higher than that of the joint by traditional MIG process.展开更多
基金Project (50905099) supported by the National Natural Science Foundation of ChinaProject (20090131120027) supported by the Specialized Research Fund for the Doctoral Program of Higher Education,China
文摘According to the differences in melting point between aluminum alloy and steel, 6013-T4 aluminum alloy was joined to galvanized steel by large spot Nd：YAG laser ＋ MIG arc hybrid brazing-fusion welding with ER4043（AlSi5） filler wire. The microstructures and mechanical properties of the brazed-fusion welded joint were investigated. The joint is divided into two parts of fusion weld and brazed seam. There is a zinc-rich zone at fusion weld toe, which consists of α（Al）-Zn solid solution and Al-Zn eutectic. The brazed seam is the Fe-Al intermetallic compounds （IMCs） layer of 2-4μm in thickness, and the IMCs include FeAl2, Fe2Al5 and Fe4Al13. FeAl2 and Fe2Al5 are located in the compact reaction layer near the steel side, and Fe4Al13 with tongue shape or sawtooth shape grows towards the fusion weld. The tensile strength of the joint firstly increases and then decreases as the welding current and laser power increase, the highest tensile strength can be up to 247.3 MPa, and the fracture usually occurs at fusion zone of the fusion weld. The hardness is the highest at the brazed seam because of hard Fe-Al IMCs, and gradually decreases along the fusion weld and galvanized steel, respectively.
基金Project(51405398) supported by the National Natural Science Foundation of China
文摘Laser-metal inert-gas(MIG)hybrid welding-brazing was applied to the butt joint of 6061-T6 aluminum alloy and 304 stainless steel.The microstructure and mechanical properties of the joint were studied.An excellent joint-section shape was achieved from good wettability on both sides of the stainless steel.Scanning electron microscopy,energy-dispersive spectroscopy and X-ray diffractometry indicated an intermetallic compound(IMC)layer at the 6061-T6/304 interface.The IMC thickness was controlled to be^2μm,which was attributed to the advantage of the laser-MIG hybrid method.Fe3Al dominated in the IMC layer at the interface between the stainless steel and the back reinforcement.The IMC layer in the remaining regions consisted mainly of Fe4Al13.A thinner IMC layer and better wettability on both sides of the stainless steel were obtained,because of the optimized energy distribution from a combination of a laser beam with a MIG arc.The average tensile strength of the joint with reinforcement using laser-MIG hybrid process was improved to be 174 MPa(60%of the 6061-T6 tensile strength),which was significantly higher than that of the joint by traditional MIG process.
