The microstructure, mechanical properties and electrical conductivity of the room-temperature and cryogenically rolled Cu-0.2wt.%Mg alloy were investigated by transmission electron microscopy (TEM), electron backscatt...The microstructure, mechanical properties and electrical conductivity of the room-temperature and cryogenically rolled Cu-0.2wt.%Mg alloy were investigated by transmission electron microscopy (TEM), electron backscattered diffraction (EBSD), hardness measurement, tensile tests and electrical conductivity measurement. The results show that for the cryorolled sample, the grain size is decreased by 41% compared with the sample processed at room temperature. With increasing thickness reduction, the microhardness of the alloy continuously increases and the electrical conductivity decreases. For the sample with 90% thickness reduction rolled at cryogenic temperature, the tensile strength and the electrical conductivity are 726 MPa and 74.5% IACS, respectively. The improved tensile strength can be mainly attributed to the grain boundaries strengthening and dislocation strengthening.展开更多
The influences of die parameters on shear strain were investigated by using two-dimensional finite element simulation.New formulas of shear strain were proposed.According to the results of formulas,the shear strain sh...The influences of die parameters on shear strain were investigated by using two-dimensional finite element simulation.New formulas of shear strain were proposed.According to the results of formulas,the shear strain showed a linear dependence on the difference between internal and external fillet radius and the slope was determined by the intersection angle.The simulation results indicated that the velocities of the points from different zones were different in the specimen and the motion trajectories of different points did not follow geometrical laws.The influences of the average velocity and the motion trajectory on shear strain were incorporated in the formula to calculate the shear strain produced during equalchannel angular pressing process.The reliability of simulation results has been partially validated by experiments.展开更多
In the present work, a CuCrZr alloy characterized by ultrafine grains and nanoscale particles was prepared by equalchannel angular pressing （ECAP） at 450℃. A desired combination of a tensile strength （580 MPa） an...In the present work, a CuCrZr alloy characterized by ultrafine grains and nanoscale particles was prepared by equalchannel angular pressing （ECAP） at 450℃. A desired combination of a tensile strength （580 MPa） and an electrical conductivity （81% International Annealed Copper Standard） is simultaneously obtained in the as-ECAP-processed CuCrZr alloy without additional aging treatment. The improved properties can be mainly attributed to the ultrafine grains and nanoscale precipitates. This processing may pave a way to develop the CuCrZr alloys having high strength and high electrical conductivity for engineering applications.展开更多
基金Project(51671064) supported by the National Natural Science Foundation of ChinaProject(HEUCFG201836) supported by the Fundamental Research Funds for the Central Universities,ChinaProject supported by the Key Laboratory of Superlight Materials & Surface Technology(Harbin Engineering University),Ministry of Education,China
文摘The microstructure, mechanical properties and electrical conductivity of the room-temperature and cryogenically rolled Cu-0.2wt.%Mg alloy were investigated by transmission electron microscopy (TEM), electron backscattered diffraction (EBSD), hardness measurement, tensile tests and electrical conductivity measurement. The results show that for the cryorolled sample, the grain size is decreased by 41% compared with the sample processed at room temperature. With increasing thickness reduction, the microhardness of the alloy continuously increases and the electrical conductivity decreases. For the sample with 90% thickness reduction rolled at cryogenic temperature, the tensile strength and the electrical conductivity are 726 MPa and 74.5% IACS, respectively. The improved tensile strength can be mainly attributed to the grain boundaries strengthening and dislocation strengthening.
基金Item Sponsored by Fundamental Research Funds for Central Universities of China(HEUCF20151002)
文摘The influences of die parameters on shear strain were investigated by using two-dimensional finite element simulation.New formulas of shear strain were proposed.According to the results of formulas,the shear strain showed a linear dependence on the difference between internal and external fillet radius and the slope was determined by the intersection angle.The simulation results indicated that the velocities of the points from different zones were different in the specimen and the motion trajectories of different points did not follow geometrical laws.The influences of the average velocity and the motion trajectory on shear strain were incorporated in the formula to calculate the shear strain produced during equalchannel angular pressing process.The reliability of simulation results has been partially validated by experiments.
基金supported by the National Natural Science Foundation of China(51671064)the Fundamental Research Funds for the Central UniversitiesKey Laboratory of Superlight Materials and Surface Technology(Harbin Engineering University),Ministry of Education
文摘In the present work, a CuCrZr alloy characterized by ultrafine grains and nanoscale particles was prepared by equalchannel angular pressing （ECAP） at 450℃. A desired combination of a tensile strength （580 MPa） and an electrical conductivity （81% International Annealed Copper Standard） is simultaneously obtained in the as-ECAP-processed CuCrZr alloy without additional aging treatment. The improved properties can be mainly attributed to the ultrafine grains and nanoscale precipitates. This processing may pave a way to develop the CuCrZr alloys having high strength and high electrical conductivity for engineering applications.
