Effect of helium on irradiation-induced hardening of iron: A simulation point of view
Effect of helium on irradiation-induced hardening of iron: A simulation point of view
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DOI：
10.1016/j.jnucmat.2007.01.187
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发表时间：
2007-05
影响因子：
3.1
通讯作者：
R. Schäublin;Y. Chiu
中科院分区：
文献类型：
--
作者：
R. Schäublin;Y. Chiu
为未来聚变反应堆设想的铁素体/马氏体材料的辐照引起的硬化和延展性损失仍然难以理解。特别是，14MeV 聚变中子嬗变产生的氦 (He) 已知会影响机械性能，但其在微观结构水平上的影响仍不清楚。对铁 (Fe) 中刃位错的迁移率进行分子动力学模拟，以研究 He 作为固溶体中或空腔中气体的影响。位错的障碍，空腔或 He 气泡形式，与 a0[100] 位错环相比，尺寸均为 2nm。结果表明，固溶体中He含量达到1.0at.%时，对位错迁移率的影响很小。相反，空洞和a0[100]位错环是刃型位错通过的强烈障碍。有趣的是，对于低 He 含量，He 气泡呈现出比空隙更低的障碍强度，而对于高 He 含量，气泡促进环冲孔，这对位错的通过产生强大的阻力。
Irradiation-induced hardening and loss of ductility of ferritic/martensitic materials envisaged for future fusion reactor is still difficult to understand. In particular, helium (He), produced by transmutation by the fusion neutrons of 14MeV, is known to impact mechanical properties, but its effect at the microstructural level is still unclear. Molecular dynamics simulations of the mobility of an edge dislocation in iron (Fe) are performed to study the effect of He, either as a gas in solid solution or in cavities. Obstacle to the dislocation, the cavity, in the form of a void or a He bubble, is compared to a a0[100] dislocation loop, all being 2nm in size. Results show that He in solid solution up to 1.0at.% has a little effect on the dislocation mobility. Conversely, the cavities and the a0[100] dislocation loop are strong obstacles to the passage of the edge dislocation. Interestingly He bubbles present a lower obstacle strength than voids for low He contents, while for high He content the bubble promotes loop punching, which induces a strong resistance to the passage of the dislocation.