The structural evolution of dislocation network is closely related to ' rafting and tensile properties.In this work,the effects of strain rate and temperature on the structural evolution of interface dislocation network in Ni-based superalloys are studied by molecular dynamics simulations.The correlation between the evolution of dislocation network and tensile properties is also explored.The results indicate that the dislocation network shows different degrees of deformation and damage at various strain rates and temperatures.The ' rafting depends on the damage structure of dislocation network at various strain rates and temperatures.Moreover,the tensile properties of interface in Ni-based superalloys are closely related to the evolution of dislocation network and dislocation motion mechanisms.
WU WenPing 1,2*,GUO YaFang 3* & WANG YueSheng 3 1 Department of Engineering Mechanics,Wuhan University,Wuhan 430072,China
The deformation behavior in magnesium single crystal under c-axis tension is investigated in a temperature range between 250 K and 570 K by molecular dynamics simulations. At a low temperature, twinning and shear bands are found to be the main deformation mechanisms. In particular, the {102} tension twins with the reorientation angle of about 90 °are observed in the simulations. The mechanisms of {102} twinning are illustrated by the simulated motion of atoms. Moreover, grain nucleation and growth are found to be accompanied with the {102} twinning. At temperatures above 450 K, the twin frequency decreases with increasing temperature. The {102} extension twin almost disappears at the temperature of 570 K. The non-basal slip plays an important role on the tensile deformation in magnesium single crystal at high temperatures.