Aluminum and stainless steel plates with 1.5 mm thickness are joined by pulsed TIG welding-brazing process with ER1100, ER4043 and ER2319 fillers, separately. Good weld formation can be obtained by adjusting appropria...Aluminum and stainless steel plates with 1.5 mm thickness are joined by pulsed TIG welding-brazing process with ER1100, ER4043 and ER2319 fillers, separately. Good weld formation can be obtained by adjusting appropriate pulse parameters. The effects of the fillers on that the thickness of the intermetallic compound （ IMC ） and tensile strength of the joints are investigated. SEM results indicate layer with ER2319 filler is about 2 ~m, which is thinner than 2. 5 p^m of ER1100 filler and 3.5 txm of ER4043 filler. Moreover, the element distribution in both IMCs and welded seams with three fillers are different because of the different compositions of fillers. The results of mechanical property tests suggest that the joint strength with ER2319 filler is the highest, while the joint impact energy is the lowest. The joint with ERllOO filler exhibits the best comprehensive mechanical pet.formanee.展开更多
Effects of Ni on microstructure and properties of aluminum-stainless steel TIG welding-brazing joint with Al-Si filler were studied. Different mass percentage of Ni powder was added in the flux separately. Results of ...Effects of Ni on microstructure and properties of aluminum-stainless steel TIG welding-brazing joint with Al-Si filler were studied. Different mass percentage of Ni powder was added in the flux separately. Results of tensile tests show that a significant improvement on mechanical properties of the butt joint is obtained using the modified flux. Moreover, obvious differences on microstructures of the interfaces were observed with Ni addition, that two intermetallic compound （IMC） layers at the interface change to one layer and the IMC thickness also decreases. Finally, effect mechanism of Ni was analyzed and discussed. Ni addition leads to an enrichment of element Si at the brazing interface, and furthermore suppresses the formation of intermetaUic compound. The reduction of IMC thickness is the main reason for the improvement of joint properties.展开更多
Dissimilar metals TIG welding-brazing of 5A06 aluminum alloy to SUS321 stainless steel has been carried out with Al-Sil2 eutectic filler metal and modified non-corrosive flux. The surface appearance and microstructure...Dissimilar metals TIG welding-brazing of 5A06 aluminum alloy to SUS321 stainless steel has been carried out with Al-Sil2 eutectic filler metal and modified non-corrosive flux. The surface appearance and microstructures of the joint were analyzed and the average tensile strength of the joint was estimated. The results show that a sound dissimilar metals joint is obtained by TIG welding-brazing. Slag and residual flux on steel surface can be removed by sanding easily. The joint has dual characteristics： in aluminum alloy side, it is a welded joint, while in stainless steel side, it is a brazed joint. The whole interface layer, unequal in thickness at different position, ranges from 5 μm to 25 μm. The average tensile strength of the butt joint reaches 120 MPa and the fracture occurs at the interface layer.展开更多
Dissimilar metals TIG welding-brazing of aluminum alloy and non-coated stainless steel was investigated. The resultant joint was characterized in order to identify the phases and the brittle intermetallic compounds （...Dissimilar metals TIG welding-brazing of aluminum alloy and non-coated stainless steel was investigated. The resultant joint was characterized in order to identify the phases and the brittle intermetallic compounds （IMCs） in the interracial layer by optical metalloscope （OM）, scanning electron microscopy （SEM） and energy dispersive spectrometer （ EDS） , and the cracked joint was analyzed in order to understand the cracking mechanism of the joint. The results show that the microfusion of the stainless steel can improve the wetting and spreading of liquid aluminum base filler metal on the steel suuface and the melted steel accelerates the formation of mass of brittle IMCs in the interracial layer, which causes the joint cracking badly. The whole interfacial layer is 5 -7 μm thick and comprises approximately 5μm-thickness reaction layer in aluminum side and about 2 μm-thickness diffusion layer in steel side. The stable Al-rich IMCs are formed in the interfacial layer and the phases transfer from （ Al ＋ FeAl3 ） in aluminum side to （ FeAl3 ＋ Fe2Al5 ） and （ α-Fe ＋ FeAl） in steel side.展开更多
A high-energy pulse power source applied for studying solidifieation of metals and a Rogowski coil for measuring strong pulse current were developed according to the requirement of the present experiment. The variatio...A high-energy pulse power source applied for studying solidifieation of metals and a Rogowski coil for measuring strong pulse current were developed according to the requirement of the present experiment. The variation of electrical current during the discharge of pulse power source was analyzed. Furthermore, the quantitative relation between peak current, pulse width and pulse frequency etc. versus voltage, capacitance and transmission line of discharging circuit was examined.展开更多
基金The authors would like to appreciate the financial support from the National Natural Science Foundation of China （Grant No. 50874033 ）.
文摘Aluminum and stainless steel plates with 1.5 mm thickness are joined by pulsed TIG welding-brazing process with ER1100, ER4043 and ER2319 fillers, separately. Good weld formation can be obtained by adjusting appropriate pulse parameters. The effects of the fillers on that the thickness of the intermetallic compound （ IMC ） and tensile strength of the joints are investigated. SEM results indicate layer with ER2319 filler is about 2 ~m, which is thinner than 2. 5 p^m of ER1100 filler and 3.5 txm of ER4043 filler. Moreover, the element distribution in both IMCs and welded seams with three fillers are different because of the different compositions of fillers. The results of mechanical property tests suggest that the joint strength with ER2319 filler is the highest, while the joint impact energy is the lowest. The joint with ERllOO filler exhibits the best comprehensive mechanical pet.formanee.
基金Acknowledgement The authors would like to appreciate the financial support from the National Natural Science Foundation of China （Grant No. 50874033）.
文摘Effects of Ni on microstructure and properties of aluminum-stainless steel TIG welding-brazing joint with Al-Si filler were studied. Different mass percentage of Ni powder was added in the flux separately. Results of tensile tests show that a significant improvement on mechanical properties of the butt joint is obtained using the modified flux. Moreover, obvious differences on microstructures of the interfaces were observed with Ni addition, that two intermetallic compound （IMC） layers at the interface change to one layer and the IMC thickness also decreases. Finally, effect mechanism of Ni was analyzed and discussed. Ni addition leads to an enrichment of element Si at the brazing interface, and furthermore suppresses the formation of intermetaUic compound. The reduction of IMC thickness is the main reason for the improvement of joint properties.
基金Supported by National Natural Science Foundation of China （50874033）.
文摘Dissimilar metals TIG welding-brazing of 5A06 aluminum alloy to SUS321 stainless steel has been carried out with Al-Sil2 eutectic filler metal and modified non-corrosive flux. The surface appearance and microstructures of the joint were analyzed and the average tensile strength of the joint was estimated. The results show that a sound dissimilar metals joint is obtained by TIG welding-brazing. Slag and residual flux on steel surface can be removed by sanding easily. The joint has dual characteristics： in aluminum alloy side, it is a welded joint, while in stainless steel side, it is a brazed joint. The whole interface layer, unequal in thickness at different position, ranges from 5 μm to 25 μm. The average tensile strength of the butt joint reaches 120 MPa and the fracture occurs at the interface layer.
基金Supported by National Natural Science Foundation of China （50874033）.
文摘Dissimilar metals TIG welding-brazing of aluminum alloy and non-coated stainless steel was investigated. The resultant joint was characterized in order to identify the phases and the brittle intermetallic compounds （IMCs） in the interracial layer by optical metalloscope （OM）, scanning electron microscopy （SEM） and energy dispersive spectrometer （ EDS） , and the cracked joint was analyzed in order to understand the cracking mechanism of the joint. The results show that the microfusion of the stainless steel can improve the wetting and spreading of liquid aluminum base filler metal on the steel suuface and the melted steel accelerates the formation of mass of brittle IMCs in the interracial layer, which causes the joint cracking badly. The whole interfacial layer is 5 -7 μm thick and comprises approximately 5μm-thickness reaction layer in aluminum side and about 2 μm-thickness diffusion layer in steel side. The stable Al-rich IMCs are formed in the interfacial layer and the phases transfer from （ Al ＋ FeAl3 ） in aluminum side to （ FeAl3 ＋ Fe2Al5 ） and （ α-Fe ＋ FeAl） in steel side.
文摘A high-energy pulse power source applied for studying solidifieation of metals and a Rogowski coil for measuring strong pulse current were developed according to the requirement of the present experiment. The variation of electrical current during the discharge of pulse power source was analyzed. Furthermore, the quantitative relation between peak current, pulse width and pulse frequency etc. versus voltage, capacitance and transmission line of discharging circuit was examined.
