With the increasing use of aluminum shape castings in structural applications in the automotive and aerospace industries,assurance of cast product integrity and performance has become critical in both design and manuf...With the increasing use of aluminum shape castings in structural applications in the automotive and aerospace industries,assurance of cast product integrity and performance has become critical in both design and manufacturing.In this paper,the latest understanding of the relationship between casting quality and mechanical properties of aluminum castings is summarized.Newly developed technologies for alloy design,melting and melt treatment,casting and heat treatment processes in aluminum casting are reviewed.The mechanical properties of aluminum castings strongly depend upon their microstructure constituents and particularly cast defect population and distribution.To produce quality castings with quantifiable properties,the key is to control multi-scale defects and microstructure in the casting.Robust design and development of high integrity aluminum castings through Integrated Computational Materials Engineering(ICME) approach is also discussed.The most effective way to optimize the processes and achieve the desirable mechanical properties is through the development and exploitation of robust and accurate multi-scale computational models.展开更多
According to the rigid-viscoplasticity finite element method,the porthole die extrusion process of an aluminum harmonica-shaped tube was successfully simulated based on software Deform-3D. The distribution of stress f...According to the rigid-viscoplasticity finite element method,the porthole die extrusion process of an aluminum harmonica-shaped tube was successfully simulated based on software Deform-3D. The distribution of stress field,effective strain field,velocity field and temperature field during the extrusion process were discussed and the metal flow in welding extrusion was analyzed. The simulation results show that the material flow velocities in the bearing exit are non-uniform with the originally designed die and the forepart of the profile is not neat or even. Aiming at solving this problem,the modification method of die structure was improved. The result shows that the uniform material flow velocities in the die exit and a perfect extruded are obtained by modification bearing length.展开更多
The mold pressing process was applied to investigate the formability of closed-cell aluminum foam in solid–liquid–gas coexisting state.Results show that the shape formation of closed-cell aluminum foam in the solid...The mold pressing process was applied to investigate the formability of closed-cell aluminum foam in solid–liquid–gas coexisting state.Results show that the shape formation of closed-cell aluminum foam in the solid–liquid–gas coexisting state was realized through cell wall deformation and cell movement caused by primary α-Al grains that slid,rotated,deformed,and ripened within cell walls.During formation,characteristic parameters of closed-cell aluminum foam were almost unchanged.Under proper forming conditions,shaped products of closed-cell aluminum foam could be fabricated through mold pressing.展开更多
文摘With the increasing use of aluminum shape castings in structural applications in the automotive and aerospace industries,assurance of cast product integrity and performance has become critical in both design and manufacturing.In this paper,the latest understanding of the relationship between casting quality and mechanical properties of aluminum castings is summarized.Newly developed technologies for alloy design,melting and melt treatment,casting and heat treatment processes in aluminum casting are reviewed.The mechanical properties of aluminum castings strongly depend upon their microstructure constituents and particularly cast defect population and distribution.To produce quality castings with quantifiable properties,the key is to control multi-scale defects and microstructure in the casting.Robust design and development of high integrity aluminum castings through Integrated Computational Materials Engineering(ICME) approach is also discussed.The most effective way to optimize the processes and achieve the desirable mechanical properties is through the development and exploitation of robust and accurate multi-scale computational models.
基金Project(50674017) supported by the National Natural Science Foundation of China
文摘According to the rigid-viscoplasticity finite element method,the porthole die extrusion process of an aluminum harmonica-shaped tube was successfully simulated based on software Deform-3D. The distribution of stress field,effective strain field,velocity field and temperature field during the extrusion process were discussed and the metal flow in welding extrusion was analyzed. The simulation results show that the material flow velocities in the bearing exit are non-uniform with the originally designed die and the forepart of the profile is not neat or even. Aiming at solving this problem,the modification method of die structure was improved. The result shows that the uniform material flow velocities in the die exit and a perfect extruded are obtained by modification bearing length.
基金financially supported by the National Natural Science Foundations of China (No.51371104)
文摘The mold pressing process was applied to investigate the formability of closed-cell aluminum foam in solid–liquid–gas coexisting state.Results show that the shape formation of closed-cell aluminum foam in the solid–liquid–gas coexisting state was realized through cell wall deformation and cell movement caused by primary α-Al grains that slid,rotated,deformed,and ripened within cell walls.During formation,characteristic parameters of closed-cell aluminum foam were almost unchanged.Under proper forming conditions,shaped products of closed-cell aluminum foam could be fabricated through mold pressing.
