In order to simultaneously take the advantages of magnesium and aluminum alloys, AZ80/A1 composite rods were produced using non-equal channel lateral extrusion （NECLE） process at different temperatures. Scanning ele...In order to simultaneously take the advantages of magnesium and aluminum alloys, AZ80/A1 composite rods were produced using non-equal channel lateral extrusion （NECLE） process at different temperatures. Scanning electron microscope （SEM） and energy dispersive spectrometer （EDS） tests as well as the shear punch test were employed to study the quality and strength of the bond between the two alloys. It was found that the process temperature was an important factor affecting the level of interfacial bonding, such that increasing the temperature from 250 to 300℃ has improved the strength by 37% and the thickness of the bond between the layers by 4.5%. Moreover, this temperature rise reduced the maximum required forming load by 13%. However, the hardness tests showed that this increase in the process temperature resulted in 4% decrease in the hardness of the composite bar.展开更多
Non-equal channel lateral extrusion（NECLE） is a new process that can be used to attain higher grain refinement in comparison with equal channel lateral extrusion（ECLE）. The die design for this process was numerica...Non-equal channel lateral extrusion（NECLE） is a new process that can be used to attain higher grain refinement in comparison with equal channel lateral extrusion（ECLE）. The die design for this process was numerically and experimentally studied. After finding a good correlation between the numerical and experimental results, more comprehensive FE analyses were carried out. Different die geometrical parameters were considered and their effects on the induced plastic strain, stress distribution, velocity field and forming load of the process were investigated. It was found that by this process with a suitable set of die geometrical parameters, higher induced effective strain and more homogeneous strain distribution could be achieved in comparison with ECLE operation.展开更多
Dual equal channel lateral extrusion (DECLE), as a severe plastic deformation (SPD) process, was employed forimproving the mechanical properties of AA5083 aluminum alloy. Several experiments were conducted to study th...Dual equal channel lateral extrusion (DECLE), as a severe plastic deformation (SPD) process, was employed forimproving the mechanical properties of AA5083 aluminum alloy. Several experiments were conducted to study the influences of theroute type, namely A and B, and pass number on mechanical properties of the material. The process was conducted up to 6 passeswith decreasing process temperature, specifically from 573 to 473 K. Supplementary experiments involving metallography, hardnessand tensile tests were carried out in order to evaluate the effects of the process variables. The hardness measurements exhibitedreasonably uniform distributions within the product with a maximum increase of 64% via a 6-pass operation. The yield and ultimatestrengths also amended 107% and 46%, respectively. These significant improvements were attributed to the severe shear deformationof grains and decreasing pass temperature, which intensified the grain refinement. TEM images showed an average grain sizereduction from 100 μm for the annealed billet to 200 nm after 6 passes of DECLE. Finally, the experimental findings for routes A andB were compared and discussed and some important conclusions were drawn.展开更多
Equal cross section lateral extrusion (ECSLE) is an effective method realizing pure shear deformation. The influence of friction factor on the deformation uniformity of ECSLE was investigated with rigid plastic finite...Equal cross section lateral extrusion (ECSLE) is an effective method realizing pure shear deformation. The influence of friction factor on the deformation uniformity of ECSLE was investigated with rigid plastic finite element method. The result shows that the non-uniform deformation in extrusion is caused mainly by the friction between workpiece and die. The higher the friction factor is, the more uneven plastic deformation resulted in extruded workpiece. The relation curve of deformation uniformity vs. friction factor was drawn based on the analysis result. The curve can be used as a basis of ECSLE process design.展开更多
A new kind of structural model, the constrained lateral extrusion, is presented based on the study of the Jurassic deformation style, combinatory pattern of several structural belts and the prototype basin development...A new kind of structural model, the constrained lateral extrusion, is presented based on the study of the Jurassic deformation style, combinatory pattern of several structural belts and the prototype basin development in western Ordos basin and its adjacent regions. The constitution,material movement and geodynamical process of the structural model are proposed. The formation mechanism and genetic relation between structural belts and prototype basins are fully studied.展开更多
arly Mesozoic flexural basins developed in East China include flexural basin with foredeep, compressive flexural basin, transpressional flexural basin and so on. Late Triassic collision between Gondwana and Eurasi...arly Mesozoic flexural basins developed in East China include flexural basin with foredeep, compressive flexural basin, transpressional flexural basin and so on. Late Triassic collision between Gondwana and Eurasian continents led to the formation of large flexural basins with foredeep. Jurassic Tethys geotectonic domain and western Pacific active continental margin activated, resulting in the formation of Early-Middle Jurassic large flexural basins and Late Jurassic small foreland basins. These basins and their marginal orogenic belts were arranged as weakly constrained lateral extrusion structures and constrained lateral extrusion structures, which show a genetic coupling relationship between the orogenic belts and the basins.展开更多
文摘In order to simultaneously take the advantages of magnesium and aluminum alloys, AZ80/A1 composite rods were produced using non-equal channel lateral extrusion （NECLE） process at different temperatures. Scanning electron microscope （SEM） and energy dispersive spectrometer （EDS） tests as well as the shear punch test were employed to study the quality and strength of the bond between the two alloys. It was found that the process temperature was an important factor affecting the level of interfacial bonding, such that increasing the temperature from 250 to 300℃ has improved the strength by 37% and the thickness of the bond between the layers by 4.5%. Moreover, this temperature rise reduced the maximum required forming load by 13%. However, the hardness tests showed that this increase in the process temperature resulted in 4% decrease in the hardness of the composite bar.
文摘Non-equal channel lateral extrusion（NECLE） is a new process that can be used to attain higher grain refinement in comparison with equal channel lateral extrusion（ECLE）. The die design for this process was numerically and experimentally studied. After finding a good correlation between the numerical and experimental results, more comprehensive FE analyses were carried out. Different die geometrical parameters were considered and their effects on the induced plastic strain, stress distribution, velocity field and forming load of the process were investigated. It was found that by this process with a suitable set of die geometrical parameters, higher induced effective strain and more homogeneous strain distribution could be achieved in comparison with ECLE operation.
基金partially supported by the Iran National Science Foundation(INSF) with grant number 92014140
文摘Dual equal channel lateral extrusion (DECLE), as a severe plastic deformation (SPD) process, was employed forimproving the mechanical properties of AA5083 aluminum alloy. Several experiments were conducted to study the influences of theroute type, namely A and B, and pass number on mechanical properties of the material. The process was conducted up to 6 passeswith decreasing process temperature, specifically from 573 to 473 K. Supplementary experiments involving metallography, hardnessand tensile tests were carried out in order to evaluate the effects of the process variables. The hardness measurements exhibitedreasonably uniform distributions within the product with a maximum increase of 64% via a 6-pass operation. The yield and ultimatestrengths also amended 107% and 46%, respectively. These significant improvements were attributed to the severe shear deformationof grains and decreasing pass temperature, which intensified the grain refinement. TEM images showed an average grain sizereduction from 100 μm for the annealed billet to 200 nm after 6 passes of DECLE. Finally, the experimental findings for routes A andB were compared and discussed and some important conclusions were drawn.
文摘Equal cross section lateral extrusion (ECSLE) is an effective method realizing pure shear deformation. The influence of friction factor on the deformation uniformity of ECSLE was investigated with rigid plastic finite element method. The result shows that the non-uniform deformation in extrusion is caused mainly by the friction between workpiece and die. The higher the friction factor is, the more uneven plastic deformation resulted in extruded workpiece. The relation curve of deformation uniformity vs. friction factor was drawn based on the analysis result. The curve can be used as a basis of ECSLE process design.
文摘A new kind of structural model, the constrained lateral extrusion, is presented based on the study of the Jurassic deformation style, combinatory pattern of several structural belts and the prototype basin development in western Ordos basin and its adjacent regions. The constitution,material movement and geodynamical process of the structural model are proposed. The formation mechanism and genetic relation between structural belts and prototype basins are fully studied.
文摘arly Mesozoic flexural basins developed in East China include flexural basin with foredeep, compressive flexural basin, transpressional flexural basin and so on. Late Triassic collision between Gondwana and Eurasian continents led to the formation of large flexural basins with foredeep. Jurassic Tethys geotectonic domain and western Pacific active continental margin activated, resulting in the formation of Early-Middle Jurassic large flexural basins and Late Jurassic small foreland basins. These basins and their marginal orogenic belts were arranged as weakly constrained lateral extrusion structures and constrained lateral extrusion structures, which show a genetic coupling relationship between the orogenic belts and the basins.
