⟨001⟩ edge dislocation nucleation mechanism of surface blistering in tungsten exposed to deuterium plasma
⟨001⟩ edge dislocation nucleation mechanism of surface blistering in tungsten exposed to deuterium plasma
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氘等离子体暴露钨表面起泡的刃位错成核机制
DOI：
10.1088/1741-4326/aaf32e
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发表时间：
2019-02-01
期刊：
影响因子：
3.3
通讯作者：
Lu, Guang-Hong
中科院分区：
文献类型：
--
作者：
Guo, Wangguo;Ge, Lin;Lu, Guang-Hong
钨 (W) 在氘 (D) 等离子体暴露下起泡的机制仍在研究中。为了清楚地展示暴露于 D 等离子体的 W 上起泡的微观结构和成核机制，制备了特殊的再结晶 W 圆盘样品，并采用背薄法进行电解抛光以用于 TEM 观察。 D等离子体暴露(2.0 x 10(26) D m(-2), 573 K)在W上产生了许多具有典型方向依赖性的晶内气泡和突起。 TEM观察揭示了颗粒内泡罩的微观结构，泡罩帽发生严重塑性变形，泡罩中心和边缘产生大量位错。由气泡位错形成的位错缠结被显露出来，并且被认为是晶内气泡的成核。通过使用g.b = 0和g.b x u = 0准则，识别出由位错缠结中的<111>边缘位错相互作用产生的具有边缘分量的<001>位错。基于先前的工作，提出了一种{001}<001>刃位错成核和起泡机制，并通过应用该机制可以很好地解释再结晶W中的起泡。专门的实验表明，晶内气泡的形成取决于局部位错密度，这验证了该机制。
The mechanism of tungsten (W) blistering under deuterium (D) plasma exposure is still under investigation. To clearly demonstrate the microstructure and nucleation mechanism of blistering on W exposed to D plasma, special recrystallized W disc samples were prepared and electropolished with back-thinned method for TEM observation. D plasma exposure (2.0 x 10(26) D m(-2), 573 K) brought it numerous intra-granular blisters and protrusions on W with typical orientation dependence. TEM observation revealed the intra-granular blister microstructure that substantial dislocations were generated on the center and edge of blister via severe plastic deformation of blister cap. Dislocation tangles formed by dislocations from blisters were revealed and supposed to be the nucleation of intra-granular blister. By using the g.b = 0 and g.b x u = 0 criterion, < 001 > dislocations with edge component were identified which were generated by < 111 > edge dislocation interaction in dislocation tangles. A {001}< 001 > edge dislocation nucleating and blistering mechanism based on previous works is proposed, and by applying which blistering in recrystallized W could be well explained. Dedicated experiments demonstrated that intra-granular blister formation depends on local dislocation density which validated the mechanism.