Blaschke Daniel N
Los Alamos National Laboratory, Computational Physics Division, Los Alamos, NM 87545, USA.
Materials (Basel). 2019 Mar 21;12(6):948. doi: 10.3390/ma12060948.
It is well known that, under plastic deformation, dislocations are not only created but also move through the crystal, and their mobility is impeded by their interaction with the crystal structure. At high stress and temperature, this "drag" is dominated by phonon wind, i.e., phonons scattering off dislocations. Employing the semi-isotropic approach discussed in detail in a previous paper ( , , 24⁻35), we discuss here the approximate functional dependence of dislocation drag on dislocation velocity in various regimes between a few percent of transverse sound speed c T and c T (where c T is the effective average transverse sound speed of the polycrystal). In doing so, we find an effective functional form for dislocation drag B ( v ) for different slip systems and dislocation characters at fixed (room) temperature and low pressure.
众所周知，在塑性变形过程中，位错不仅会产生，还会在晶体中移动，并且它们的迁移率会因与晶体结构的相互作用而受到阻碍。在高应力和高温下，这种“拖拽”主要由声子风主导，即声子从位错上散射。采用先前一篇论文（，，24⁻35）中详细讨论的半各向同性方法，我们在此讨论在横向声速(c_T)的百分之几到(c_T)（其中(c_T)是多晶体的有效平均横向声速）之间的各种状态下，位错拖拽与位错速度的近似函数关系。通过这样做，我们在固定（室温）温度和低压下，为不同的滑移系统和位错特征找到了位错拖拽(B(v))的有效函数形式。
