Plasma-MIG {metal inert gas arc welding） hybrid welding of aluminum alloy with 6 mm thickness using ER5356 welding wire was carried out. The microstructures and mechanical properties of the welded joint were inve...Plasma-MIG {metal inert gas arc welding） hybrid welding of aluminum alloy with 6 mm thickness using ER5356 welding wire was carried out. The microstructures and mechanical properties of the welded joint were investigated by optical microscopy, X-ray diffraction （XRD） , energy dispersive spectroscopy （EDS） , tensile test, hardness test and scanning electron microscope （ SEM） were used to judge the type of tensile fracture. The results showed that the tensile strength of welded joint was 142 MPa which was 53. 6% o f the strength o f the base metal. The welding seam zone was characterized by dendritic structure. In the fusion zone, the columnar grains existed at one side of the welding seam. The fibrous organization was found in the base metal, and also in the heat affected zone （HAZ） where the recrystallization occurred. The HAZ was the weakest position of the welded joint due to the coarsening of Mg2Si phase. The type of tensile fracture was ductile fracture.展开更多
A three-dimensional simulation model for the plasma-MIG welding process, which takes the interaction between the plasma arc and MIG arc into account, is presented and the quasi-steady temperature fields on the workpie...A three-dimensional simulation model for the plasma-MIG welding process, which takes the interaction between the plasma arc and MIG arc into account, is presented and the quasi-steady temperature fields on the workpiece are calculated with the model. The 10 mm-5A06 aluminum alloy is welded and the temperature fields are measured with the thermoelectric couple. The simulation results and measured results show that the biggest deviation of peak temperature between them is below 20 ℃, which indicates good coincidence between the simulation and measurement.展开更多
The influence of heating cycles during plasma metal inert gas (MIG) welding on the microstructure and corrosion properties of the AA5754 automotive alloy has been investigated. The high heat input during plasma-MIG we...The influence of heating cycles during plasma metal inert gas (MIG) welding on the microstructure and corrosion properties of the AA5754 automotive alloy has been investigated. The high heat input during plasma-MIG welding results in a significant modification in the microstructure of the AA5754 alloy adjacent to the fusion boundaries. As a consequence of partial melting of the Al-Fe-Mn-(Si) intermetallics at the partially melted zone (PMZ) and segregation of the high melting point elements (particularly Fe and Mn) toward the fusion zone, severe galvanic corrosion attacks can be enhanced along the PMZ of the AA5754 weld during exposure to aqueous corrosion environments.展开更多
The plasma-MIG welding torch was developed.5A06 aluminum alloys with V-grooves were welded in a single pass in the plasma-MIG welding process and the joints were examined by X-ray diffractometry analysis and mechanica...The plasma-MIG welding torch was developed.5A06 aluminum alloys with V-grooves were welded in a single pass in the plasma-MIG welding process and the joints were examined by X-ray diffractometry analysis and mechanical tests.The orthogonal experimental design was used to study the influence of plasma-MIG welding parameters on the aluminum weld porosity.The mixed orthogonal matrix L16(4 4×2 3) and analysis of variance (ANOVA)technique were employed to optimize the welding parameters.The experimental results indicate that the effect of plasma gas flow rate is dominant,the secondary factors are MIG welding voltage,welding speed,wire feed rate and plasma current in turn.Confirmation experiments were conducted under optimum conditions and there was almost no porosity in the welded joints,thus good mechanical performance joints were obtained.展开更多
The synchronous acquisition system of droplet image inspection and arc electric signals were established and the droplet transition characteristics of aluminum alloys were researched in the plasma-MIG welding process....The synchronous acquisition system of droplet image inspection and arc electric signals were established and the droplet transition characteristics of aluminum alloys were researched in the plasma-MIG welding process.Typical droplet transition modes include globular transfer mode,short circuiting transfer mode,metastable spray transfer mode and projected transfer mode.The result indicates that MIG droplet transfer frequency and droplet transfer modes are changed by introducing the plasma arc in the plasma-MIG welding process compared with the MIG welding on the aluminum alloys,which broadens the range of welding parameters when the stable welding process proceeds.The metastable spray transfer and projected transfer mode are proved to be the most optimal modes by comparing the stability of electronic signal,droplet transition,weld appearance and weld penetration.展开更多
Plasma-MIG hybrid arc welding is a hybrid heating source welding method which is composed of plasma arc and MIG arc. During Plasma-MIG hybrid arc welding process, the interface behavior of copper and steel dissimilar ...Plasma-MIG hybrid arc welding is a hybrid heating source welding method which is composed of plasma arc and MIG arc. During Plasma-MIG hybrid arc welding process, the interface behavior of copper and steel dissimilar alloy is investigated. The results show that electromagnetic stirring effect decreases and the heat input increases with the increase of outer plasma current in the hybrid arc welding process. The interface diffusion and interface thickness is controlled by the tradeoff of electromagnetic stirring effect degradation and heat input increase. The interface diffusion and interface thickness are controlled by decreasing the electromagnetic stirring force and increasing the heat input with the increase of plasma current in Cu/Fe plasma-MIG hybrid arc welding process.展开更多
基金Key Laboratory of Advanced Welding Technology of Jiangsu University of Science and Technology (Grant NO. JSAWT-11-02) for its financial support
文摘Plasma-MIG {metal inert gas arc welding） hybrid welding of aluminum alloy with 6 mm thickness using ER5356 welding wire was carried out. The microstructures and mechanical properties of the welded joint were investigated by optical microscopy, X-ray diffraction （XRD） , energy dispersive spectroscopy （EDS） , tensile test, hardness test and scanning electron microscope （ SEM） were used to judge the type of tensile fracture. The results showed that the tensile strength of welded joint was 142 MPa which was 53. 6% o f the strength o f the base metal. The welding seam zone was characterized by dendritic structure. In the fusion zone, the columnar grains existed at one side of the welding seam. The fibrous organization was found in the base metal, and also in the heat affected zone （HAZ） where the recrystallization occurred. The HAZ was the weakest position of the welded joint due to the coarsening of Mg2Si phase. The type of tensile fracture was ductile fracture.
文摘A three-dimensional simulation model for the plasma-MIG welding process, which takes the interaction between the plasma arc and MIG arc into account, is presented and the quasi-steady temperature fields on the workpiece are calculated with the model. The 10 mm-5A06 aluminum alloy is welded and the temperature fields are measured with the thermoelectric couple. The simulation results and measured results show that the biggest deviation of peak temperature between them is below 20 ℃, which indicates good coincidence between the simulation and measurement.
文摘The influence of heating cycles during plasma metal inert gas (MIG) welding on the microstructure and corrosion properties of the AA5754 automotive alloy has been investigated. The high heat input during plasma-MIG welding results in a significant modification in the microstructure of the AA5754 alloy adjacent to the fusion boundaries. As a consequence of partial melting of the Al-Fe-Mn-(Si) intermetallics at the partially melted zone (PMZ) and segregation of the high melting point elements (particularly Fe and Mn) toward the fusion zone, severe galvanic corrosion attacks can be enhanced along the PMZ of the AA5754 weld during exposure to aqueous corrosion environments.
文摘The plasma-MIG welding torch was developed.5A06 aluminum alloys with V-grooves were welded in a single pass in the plasma-MIG welding process and the joints were examined by X-ray diffractometry analysis and mechanical tests.The orthogonal experimental design was used to study the influence of plasma-MIG welding parameters on the aluminum weld porosity.The mixed orthogonal matrix L16(4 4×2 3) and analysis of variance (ANOVA)technique were employed to optimize the welding parameters.The experimental results indicate that the effect of plasma gas flow rate is dominant,the secondary factors are MIG welding voltage,welding speed,wire feed rate and plasma current in turn.Confirmation experiments were conducted under optimum conditions and there was almost no porosity in the welded joints,thus good mechanical performance joints were obtained.
文摘The synchronous acquisition system of droplet image inspection and arc electric signals were established and the droplet transition characteristics of aluminum alloys were researched in the plasma-MIG welding process.Typical droplet transition modes include globular transfer mode,short circuiting transfer mode,metastable spray transfer mode and projected transfer mode.The result indicates that MIG droplet transfer frequency and droplet transfer modes are changed by introducing the plasma arc in the plasma-MIG welding process compared with the MIG welding on the aluminum alloys,which broadens the range of welding parameters when the stable welding process proceeds.The metastable spray transfer and projected transfer mode are proved to be the most optimal modes by comparing the stability of electronic signal,droplet transition,weld appearance and weld penetration.
基金financially supported by the National Natural Science Foundation of China (Nos. 50974046 and 50904020)Twelfth Five-year Aerospace Project of China
文摘Plasma-MIG hybrid arc welding is a hybrid heating source welding method which is composed of plasma arc and MIG arc. During Plasma-MIG hybrid arc welding process, the interface behavior of copper and steel dissimilar alloy is investigated. The results show that electromagnetic stirring effect decreases and the heat input increases with the increase of outer plasma current in the hybrid arc welding process. The interface diffusion and interface thickness is controlled by the tradeoff of electromagnetic stirring effect degradation and heat input increase. The interface diffusion and interface thickness are controlled by decreasing the electromagnetic stirring force and increasing the heat input with the increase of plasma current in Cu/Fe plasma-MIG hybrid arc welding process.
