图 1  $ {\boldsymbol{b}}/ / {\boldsymbol{n}} $位错环的取向变化和分解($T = 800$ K, 初始深度$h = 5$ nm)　(a) $t = 0.001$; (b) $t = 0.018$; (c) $t = 0.115$; (d) $t = $$ 0.170$; (e) $t = 0.239$; (f) $t = 0.245$; (g) $t = 0.246$; (h) $t = 0.247$; 图中粉红颜色代表$\langle 100\rangle $位错, 绿颜色代表${1 \mathord{\left/ {\vphantom {1 2}} \right. } 2}\langle 111\rangle $位错, 蓝色箭头表示柏氏矢量方向

Figure 1.  Orientational change and decomposition of a $ {\boldsymbol{b}}/ / {\boldsymbol{n}} $ dislocation loop at $T = 800$ K and the initial depth of $h = 5$ nm: (a) $t = 0.001$; (b) $t = 0.018$; (c) $t = 0.115$; (d) $t = 0.170$; (e) $t = 0.239$; (f) $t = 0.245$; (g) $t = 0.246$; (h) $t = 0.247$. The pink loop stands for the $\langle 100\rangle $ type dislocation, the green one for ${1 \mathord{\left/ {\vphantom {1 2}} \right. } 2}\langle 111\rangle $. The blue arrows denote the direction of Burgers vector.

图 2  $ {\boldsymbol{b}}/ / {\boldsymbol{n}} $位错环移动过程中的应力变化图($T = 800$ K, 初始深度$h = 5$ nm)　(a)—(e) 位错环向表面移动过程中的应力图, 其中(a) t = 0.014, (b) t = 0.018, (c) t = 0.066, (d) t = 0.115, (e) t = 0.239; (f) 位错环完全移出表面后的应力图, t = 0.247

Figure 2.  Stress variation of a $ {\boldsymbol{b}}/ / {\boldsymbol{n}} $ dislocation loop at $T = 800$ K and initial depth of $h = 5$ nm in motion: (a)–(e) The stress of the dislocation loop as it moves toward the surface ((a) t = 0.014, (b) t = 0.018, (c) t = 0.066, (d) t = 0.115, (e) t = 0.239); (f) the stress after the dislocation loop has been completely removed from the surface, t = 0.247.

图 3  $ {\boldsymbol{b}}/ / {\boldsymbol{n}} $位错环与表面相互作用后的表面形貌

Figure 3.  Surface morphology after the interaction between $ {\boldsymbol{b}}/ / {\boldsymbol{n}} $ dislocation loop and surface has ceased to occur.

图 4  $ {\boldsymbol{b}}/ / {\boldsymbol{n}} $位错环演化过程中位错类型变化图　(a) 位错环未与表面发生作用时的状态; (b) 位错环与表面发生强烈作用时的状态. 图中蓝色为刃位错, 红色为螺位错

Figure 4.  Variation of the dislocation geometry of a $ {\boldsymbol{b}}/ / {\boldsymbol{n}} $ dislocation loop in motion: (a) The geometry of the dislocation loop away from the surface; (b) the geometry change of the dislocation loop while interacting with the surface. Blue represents the edge dislocation, red represents a screw dislocation.

图 5  $ {\boldsymbol{b}} \bot {\boldsymbol{n}} $ 型位错环的取向变化和分解($T = 800$ K)　(a) $t = 0.018$; (b) $t = 0.115$; (c) $t = 0.170$; (d) $t = 0.245$; (e) $t = $$ 0.246$; (f) $t = 0.247$; 图中粉红颜色的为$\langle 100\rangle $型位错, 绿颜色的为${1 \mathord{\left/ {\vphantom {1 2}} \right. } 2}\langle 111\rangle $型位错, 底部物理量代表位错环初始深度

Figure 5.  Orientational change and decomposition of a $ {\boldsymbol{b}} \bot {\boldsymbol{n}} $ dislocation loop at $T = 800$ K: (a) $t = 0.018$; (b) $t = 0.115$; (c) $t = 0.170$; (d) $t = 0.245$; (e) $t = 0.246$; (f) $t = 0.247$. The pink loop stands for the $\langle 100\rangle $ dislocation, the green part for ${1 \mathord{\left/ {\vphantom {1 2}} \right. } 2}\langle 111\rangle $, the physical quantity at the bottom represents the initial depth of the dislocation loop.

图 6  位错环($ {\boldsymbol{b}}/ / {\boldsymbol{n}} $和$ {\boldsymbol{b}} \bot {\boldsymbol{n}} $)形成能随距离表面深度的变化

Figure 6.  Variation of the formation energies of the dislocation loops ($ {\boldsymbol{b}}/ / {\boldsymbol{n}} $ and $ {\boldsymbol{b}} \bot {\boldsymbol{n}} $) with increasing depth.

图 8  不同温度和深度下$ {\boldsymbol{b}}/ / {\boldsymbol{n}} $位错环的滞留时间变化, 图中编号1—10, 11—20 和21—30分别是初始深度$h = $$ 3, 5, 7$nm的位错环

Figure 8.  Retention time variation of the $ {\boldsymbol{b}}/ / {\boldsymbol{n}} $ dislocation loops with temperature and depth. The numbers 1−10, 11−20, and 21−30 are used to specify the dislocation loops located at the initial depth of $h = 3, 5, 7$nm, respectively.

图 7  位错环($ {\boldsymbol{b}}/ / {\boldsymbol{n}} $和$ {\boldsymbol{b}} \bot {\boldsymbol{n}} $)映像力随距离表面深度的变化

Figure 7.  Image forces of the dislocation loops ($ {\boldsymbol{b}}/ / {\boldsymbol{n}} $ and $ {\boldsymbol{b}} \bot {\boldsymbol{n}} $) with increasing depth.

图 9  位错环与氦间隙原子对的结合能　(a), (b) $ {\boldsymbol{b}}/ / {\boldsymbol{n}} $位错环分别在方向Ⅰ和方向Ⅱ上的结和能; (c), (d) $ {\boldsymbol{b}} \bot {\boldsymbol{n}} $位错环分别在方向Ⅰ和方向Ⅱ上的结和能, $ {\text{loo}}{{\text{p}}_{1}}—{\text{loo}}{{\text{p}}_{5}} $分别对应$h = 1.5, {\kern 1 pt} {\kern 1 pt} {\kern 1 pt} {\kern 1 pt} 2, {\kern 1 pt} {\kern 1 pt} {\kern 1 pt} 2.5, {\kern 1 pt} {\kern 1 pt} {\kern 1 pt} 3, {\kern 1 pt} {\kern 1 pt} {\kern 1 pt} 3.5$ nm的位错环. (a), (c) 横坐标是氦原子对距离位错环的距离; (b), (d) 横坐标是氦原子对距表面的深度

Figure 9.  Binding energy of the dislocation loop with a pair of helium atoms: (a), (b) The binding energies in direction Ⅰ and Ⅱ of $ {\boldsymbol{b}}/ / {\boldsymbol{n}} $ dislocation loops; (c), (d) the binding energies for the $ {\boldsymbol{b}} \bot {\boldsymbol{n}} $ dislocation loop. $ {\text{loo}}{{\text{p}}_{1}}-{\text{loo}}{{\text{p}}_{5}} $ correspond to the dislocation loops located at $h = 1.5, {\kern 1 pt} {\kern 1 pt} {\kern 1 pt} {\kern 1 pt} 2, {\kern 1 pt} {\kern 1 pt} {\kern 1 pt} 2.5, {\kern 1 pt} {\kern 1 pt} {\kern 1 pt} 3, {\kern 1 pt} {\kern 1 pt} {\kern 1 pt} 3.5$ nm. The abscissa of (a) and (c) represents the distances between the pair of helium atoms and the dislocation loop, and the ordinate of (b) and (d) is for the depth.

图 10  不同温度下$ {\boldsymbol{b}}/ / {\boldsymbol{n}} $位错环的滞留时间图(体系中含氦原子对) 图中编号1 — 10, 11—20和21—30分别是初始深度h = 3 , 5 , 7 nm的位错环

Figure 10.  Variation of the retention time with temperature and depth for the $ {\boldsymbol{b}}/ / {\boldsymbol{n}} $ dislocation loops existing in the W lattice cell containing a pair of helium atoms. The numbers 1–10, 11–20, and 21–30 are used to specify the dislocation loops located at the initial depth of $h = 3, 5, 7$nm, respectively.

图 A1  不同温度$ {\boldsymbol{b}} \bot {\boldsymbol{n}} $位错环的运动演化过程(初始深度h = 5 nm)　(a) $t = 0.980$; (b) $t = 2.000$; (c) $t = 0.980$; (d) $t = 2.000$; (e) $t = 0.540$; (f) $t = 0.960$; (g) $t = 1.600$; (h) $t = 2.000$; 图中粉红颜色的为$\langle 100\rangle $型位错, 绿颜色的为${1 \mathord{\left/ {\vphantom {1 2}} \right. } 2}\langle 111\rangle $型位错

Figure A1.  Orientational change and decomposition of a $ {\boldsymbol{b}} \bot {\boldsymbol{n}} $ dislocation loop at the initial depth of $h = 5$ nm: (a) $t = 0.980$; (b) $t = 2.000$; (c) $t = 0.980$; (d) $t = 2.000$; (e) $t = 0.540$; (f) $t = 0.960$; (g) $t = 1.600$; (h) $t = 2.000$. The pink loop stands for the $\langle 100\rangle $ type dislocation, the green one for ${1 \mathord{\left/ {\vphantom {1 2}} \right. } 2}\langle 111\rangle $.