A Fe/Al clad tube was prepared by explosive welding.Then the bonding characteristic of the interface was investigated by compression,flattening and compression-shear test.The test results exhibit that the clad tubes p...A Fe/Al clad tube was prepared by explosive welding.Then the bonding characteristic of the interface was investigated by compression,flattening and compression-shear test.The test results exhibit that the clad tubes possessing good bonding interface have higher shear strength than that of pure aluminum and can bear both axial and radial deformation.The original interface between aluminum layer and ferrite layer was observed by scanning electron microscopy（SEM）.The results show that the clad tubes with good bonding properties possess the interface in wave and straight shape.The Fe/Al clad tube was used to manufacture the T-shape by hydro-bulging.It is found that the good-bonding interface of the Fe/Al clad tube plays a dominant role in the formation of the T-shape.展开更多
A simultaneous prediction of macroscopic deformation and microstructure evolution is critical for un-derstanding the deformation mechanism of components.In this work,the hydro-bulging process of 2219 aluminum alloy sh...A simultaneous prediction of macroscopic deformation and microstructure evolution is critical for un-derstanding the deformation mechanism of components.In this work,the hydro-bulging process of 2219 aluminum alloy sheet was investigated using cross-scale numerical modeling,in which the macroscopic finite element method(FEM)and crystal plasticity finite element method(CPFEM)were combined.The calculated texture evolution exhibits good agreement with the experimental results,and the stress er-ror between the two scales is generally small.The effects of different strain states on texture evolution and slip mode are further discussed.As the strain ratioηincreases,the volume fractions of the initial Rotated Copper texture component andγ-Fiber texture component decrease significantly,which tend to be stabilized at P texture component.The initial Rotated Cube texture component is inclined to rotate towards the Cube texture component,while the volume fraction of this orientation is relatively stable.The lower strain ratio can considerably enhance the activity of more equivalent slip systems,promoting a more uniform strain distribution over grains.The difficulty of grain deformation changes as the lat-tice rotates.The grain with easy-to-deform orientation can gradually rotate to a stable orientation during plastic deformation,which has a lower Schmid factor.展开更多
Based on the assumption that profile of thin walled tube in free hydro-bulging process is a quadratic curve and any point on the profile moves vertically to the profile, mathematical models were deduced for analyzing ...Based on the assumption that profile of thin walled tube in free hydro-bulging process is a quadratic curve and any point on the profile moves vertically to the profile, mathematical models were deduced for analyzing the deformation behavior. The critical pressure and the maximum bulge coefficient(height) at bursting can be determined based on the models, in which a shape factor a is introduced to tightly communicate the material property and geometric parameters to plastic deformation. Free hydro-bulging experiments of stainless steel and low carbon steel tubes were conducted to validate the models, and the experimental data indicate that the theoretical predictions are reliable and accurate. The results display that the profile, dependent on the material and geometric parameters, can be hyperbola, parabola, arc and ellipse or alternative among them; moreover, the forming pressure and forming limit are both closely connected with material and geometric parameters.展开更多
This paper introduces the principle and procedure of integral hydro-forming technology for spherical vessels and the elastoplastic stress fields near weld seams. It also presents mechanical models of the angular disto...This paper introduces the principle and procedure of integral hydro-forming technology for spherical vessels and the elastoplastic stress fields near weld seams. It also presents mechanical models of the angular distortion area, which explains the circularization bending moment and the effect of spherodization in the angular distortion area during the process of hydro-bulging.展开更多
基金Project(BA2006067)supported by Achievement Transitional Foundation of Jiangsu Province,China
文摘A Fe/Al clad tube was prepared by explosive welding.Then the bonding characteristic of the interface was investigated by compression,flattening and compression-shear test.The test results exhibit that the clad tubes possessing good bonding interface have higher shear strength than that of pure aluminum and can bear both axial and radial deformation.The original interface between aluminum layer and ferrite layer was observed by scanning electron microscopy（SEM）.The results show that the clad tubes with good bonding properties possess the interface in wave and straight shape.The Fe/Al clad tube was used to manufacture the T-shape by hydro-bulging.It is found that the good-bonding interface of the Fe/Al clad tube plays a dominant role in the formation of the T-shape.
基金financially supported by the National Natural Science Foundation of China(No.52275322)the Heilongjiang Touyan Team(No.HITTY-20190015).
文摘A simultaneous prediction of macroscopic deformation and microstructure evolution is critical for un-derstanding the deformation mechanism of components.In this work,the hydro-bulging process of 2219 aluminum alloy sheet was investigated using cross-scale numerical modeling,in which the macroscopic finite element method(FEM)and crystal plasticity finite element method(CPFEM)were combined.The calculated texture evolution exhibits good agreement with the experimental results,and the stress er-ror between the two scales is generally small.The effects of different strain states on texture evolution and slip mode are further discussed.As the strain ratioηincreases,the volume fractions of the initial Rotated Copper texture component andγ-Fiber texture component decrease significantly,which tend to be stabilized at P texture component.The initial Rotated Cube texture component is inclined to rotate towards the Cube texture component,while the volume fraction of this orientation is relatively stable.The lower strain ratio can considerably enhance the activity of more equivalent slip systems,promoting a more uniform strain distribution over grains.The difficulty of grain deformation changes as the lat-tice rotates.The grain with easy-to-deform orientation can gradually rotate to a stable orientation during plastic deformation,which has a lower Schmid factor.
文摘Based on the assumption that profile of thin walled tube in free hydro-bulging process is a quadratic curve and any point on the profile moves vertically to the profile, mathematical models were deduced for analyzing the deformation behavior. The critical pressure and the maximum bulge coefficient(height) at bursting can be determined based on the models, in which a shape factor a is introduced to tightly communicate the material property and geometric parameters to plastic deformation. Free hydro-bulging experiments of stainless steel and low carbon steel tubes were conducted to validate the models, and the experimental data indicate that the theoretical predictions are reliable and accurate. The results display that the profile, dependent on the material and geometric parameters, can be hyperbola, parabola, arc and ellipse or alternative among them; moreover, the forming pressure and forming limit are both closely connected with material and geometric parameters.
文摘This paper introduces the principle and procedure of integral hydro-forming technology for spherical vessels and the elastoplastic stress fields near weld seams. It also presents mechanical models of the angular distortion area, which explains the circularization bending moment and the effect of spherodization in the angular distortion area during the process of hydro-bulging.
