The Dynamic Behavior of Ultra-Fine-Grained Copper Fabricated by Equal Channel Angular Pressing
The high-strain-rate response of ultrafine-grained (UFG) copper fabricated by equal channel angular pressing (ECAP) has been characterized by Split Hopkinson Pressure Bar (SHPB) test and quasistatic compression test has also been performed for comparison here. In the result of quasi-static tests a maximum yield stress equal to 432 MPa has been reached, at the same time the corresponding value turned out to be 995 MPa after a dynamic loading with the strain rate equal to 1700 s~. It has been demonstrated that the strain rate sensitivity coefficient (m) has enhanced from 0.026 (coarsegrained copper) to 0.037 (UFG copper). Microstructure has indicated a high dislocation density and deformation twins inside the grains formed after a high-strain-rate deformation, which resulted in a high flow stress. The occurrence of a dynamic recrystallization has also been observed in the UFG copper subjected to high-strain-rate deformation. This has become apparent as an accelerated thermal softening and inherent instability typical for the UFG structure. Absence of adiabatic shear bands pointed out that UFG copper can be subjected to a dynamic impact without any fracture.
Y.C.Dong I.V.Alexandrov J.T.Wang
The Department of Physics,Ufa State Aviation Technical University,450000 Ufa,Russia School of Materi The Department of Physics,Ufa State Aviation Technical University,450000 Ufa,Russia School of Materials Science and Engineering,Nanjing University of Science and Technology,Nanjing,Jia
国际会议
5th International Conference on Nanomaterials by Severe Plastic Deformation(第五届剧烈塑性变形纳米材料国际会议)
南京
英文
891-896
2011-03-01（万方平台首次上网日期，不代表论文的发表时间）