Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Phys Rev Lett. 2010 Aug 27;105(9):095501. doi: 10.1103/PhysRevLett.105.095501. Epub 2010 Aug 23.
Here we report kinetic Monte Carlo simulations of dislocation climb in heavily deformed, body-centered cubic iron comprising a supersaturation of vacancies. This approach explicitly incorporates the effect of nonlinear vacancy-dislocation interaction on vacancy migration barriers as determined from atomistic calculations, and enables observations of diffusivity and climb over time scales and temperatures relevant to power-law creep. By capturing the underlying microscopic physics, the calculated stress exponents for steady-state creep rates agree quantitatively with the experimentally measured range, and qualitatively with the stress dependence of creep activation energies.
我们在此报告了在包含过饱和度空位的严重变形体心立方铁中位错攀移的动力学蒙特卡罗模拟。这种方法明确地纳入了原子计算确定的空位-位错相互作用的非线性对空位迁移势垒的影响,并能够观察到与幂律蠕变相关的时间尺度和温度下的扩散和攀移。通过捕捉潜在的微观物理,计算得到的稳态蠕变速率的应力指数与实验测量范围在定量上一致,并与蠕变激活能的应力依赖性在定性上一致。