The capability of the torsion extrusion （TE） process as a severe plastic deformation （SPD） method was compared with the conventional forward extrusion （FE） process. The TE and FE processes were successfully perf...The capability of the torsion extrusion （TE） process as a severe plastic deformation （SPD） method was compared with the conventional forward extrusion （FE） process. The TE and FE processes were successfully performed on AA1050 alloy samples at room temperature. To simulate the above mentioned processes, finite element analysis was carried out using the commercial elasto-plastic finite element analysis ABAQUS/Explicit Simulation. It is shown that load requirement for the TE process is lower than that for the FE process. The equivalent plastic strain calculated by the FEA proved that higher values of strain are imposed to the sample in the TE process. The strain distribution for the TE sample at the final stage of extrusion shows smoother strain gradient in comparison with the one produced by the FE process.展开更多
To investigate the effects of pressure on the hot isostatic pressing(HIP) process of a stainless steel powder,density distribution and deformation of the powder at four different applied pressure levels were predicted...To investigate the effects of pressure on the hot isostatic pressing(HIP) process of a stainless steel powder,density distribution and deformation of the powder at four different applied pressure levels were predicted and compared by using finite element method(FEM).Constitutive relations of porous compacts during HIP process were derived based on the yield criterion of porous metal materials.Thermo-mechanical coupling calculations were carried out by the MSC.Marc.Densification mechanisms were studied through evolutions of relative density,equivalent plastic strain and equivalent viscoplastic strain rate for compacts.The simulation results were also compared with experimental data.The results show that the densification rate and final density of compacts increase dramatically with the increase in the applied pressure level when it is below 100 MPa during HIP process,and the creep for compacts evolves into steady stage with the improvement of density.展开更多
基金been conducted using research grants of Islamic Azad University,Shiraz Branch
文摘The capability of the torsion extrusion （TE） process as a severe plastic deformation （SPD） method was compared with the conventional forward extrusion （FE） process. The TE and FE processes were successfully performed on AA1050 alloy samples at room temperature. To simulate the above mentioned processes, finite element analysis was carried out using the commercial elasto-plastic finite element analysis ABAQUS/Explicit Simulation. It is shown that load requirement for the TE process is lower than that for the FE process. The equivalent plastic strain calculated by the FEA proved that higher values of strain are imposed to the sample in the TE process. The strain distribution for the TE sample at the final stage of extrusion shows smoother strain gradient in comparison with the one produced by the FE process.
基金Project(2007AA03Z115) supported by the National High Technology Research and Development Program of ChinaProject(2009ZX04005-041-03) supported by the National Science and Technology Major Program of ChinaProject(2010MS046) supported by the Independent Fund of Huazhong University of Science and Technology,China
文摘To investigate the effects of pressure on the hot isostatic pressing(HIP) process of a stainless steel powder,density distribution and deformation of the powder at four different applied pressure levels were predicted and compared by using finite element method(FEM).Constitutive relations of porous compacts during HIP process were derived based on the yield criterion of porous metal materials.Thermo-mechanical coupling calculations were carried out by the MSC.Marc.Densification mechanisms were studied through evolutions of relative density,equivalent plastic strain and equivalent viscoplastic strain rate for compacts.The simulation results were also compared with experimental data.The results show that the densification rate and final density of compacts increase dramatically with the increase in the applied pressure level when it is below 100 MPa during HIP process,and the creep for compacts evolves into steady stage with the improvement of density.
