核石墨中的动态变形及其潜在机制
Melonie Thomas1, Hajin Oh1, Ryan Schoell2
1Department of Mechanical Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
Materials (Basel, Switzerland)
|September 28, 2024
概括
核石墨 (IG-110) 中先前存在的缺陷显著影响辐射诱导的变形. 莫佐夫斯基裂促进局部可塑性,而辐射类型影响爬行行为和脆化.
科学领域:
- 材料科学 材料科学 材料科学
- 核工程 核工程是指核工程.
- 固体力学 固体力学是什么
背景情况:
- 核石墨的性能对于反应堆的性能和安全至关重要.
- 辐射引起的缺陷和先前存在的缺陷,如Mrozowski裂,会影响石墨的机械行为.
- 了解在辐射下依赖时间的变形对于核应用至关重要.
研究的目的:
- 为了研究核石墨 (IG-110) 辐射下先前存在的缺陷 (点缺陷集群,Mrozowski裂) 的作用.
- 分析不同类型的离子 (Au2+和C2+) 和辐射条件对石墨机械反应的影响.
- 阐明核石墨中辐射诱导的变形和脆化的机制.
主要方法:
- 在特定的度下,用2.8 MeV Au2+和8 MeV C2+光束对IG-110石墨进行辐射.
- 在传输电子显微镜 (TEM) 内的微观标本的现场机械加载.
- 现场基于痕的爬行载荷实验.
主要成果:
- 在现场的TEM揭示了Mrozowski裂周围的局部塑性,形成滑动或波动带.
- 只有在非常高的压力下,在没有缺陷的区域附近才观察到滑带.
- 现场自我离子辐射导致了脆化和减少爬行,而重离子辐射显示了相反的效果.
- 假设大金离子诱导胀和缺陷移动通道.
结论:
- 预先存在的缺陷在辐射期间核石墨的动态应力放松中发挥着关键作用.
- 照射的类型显著改变了机械反应,包括脆化和爬行.
- 需要进一步的研究才能充分理解辐射环境和石墨的机械特性之间的复杂相互作用.
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