Evolution of perturbations of temperature and dislocation density at high-rate shear deformation of pure metals and alloys
We have investigated numerically an evolution of initial perturbations of temperature or dislocation density in metals at high-rate deformation and its influence on the localization of plastic flow. A high-rate simple shear of micro-samples of pure metals and alloys, coarse-grained as well as nano-crystalline, has been simulated in two-dimensional geometry with use of the continuum mechanics supplemented by the dislocation plasticity and the grain-boundary sliding models. Perturbations of the temperature or dislocation density lead to restricted localization of the plastic deformation, but they can not initiate instability of the plastic flow as a self-sustained and increasing process. A more effective reason of the localization is the stress concentration, caused, for example, by boundary conditions. Rate of the plastic deformation is maximal in areas of the shear stress localization and it can be close to zero outside these areas. Heterogeneity of the grain sizes distribution through the sample can also lead to substantial localization of the plastic flow due to the grain size dependence of the dynamic yield strength.
High-rate plasticity Localization Temperature perturbation Dislocations Metals
Alexander E.Mayer Elijah N.Borodin Polina N.Mayer Yury V.Vorobyov Dmitry A.Tikhonov
Department of Physics,Chelyabinsk State University,Chelyabinsk,454001,Russia Department of Physics,Chelyabinsk State University,Chelyabinsk,454001,Russia;Institute of Problems o
国际会议
北京
英文
1-9
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）