Wang Shuming, Li Jiangshan, Wang Ye, Zhang Xiaofang, Wang Ruiping, Wang Yanru, Cao Jian
Department of Materials Science and Engineering, University of Science &Technology Beijing, Beijing, 100083, China.
State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin, 150001, China.
Sci Rep. 2020 Jan 28;10(1):1359. doi: 10.1038/s41598-020-57852-8.
Fusion energy is expected as a promising candidate for alternative next generation energy. For fusion reactor, the plasma facing components (PFCs) are the most critical components to achieve this goal. PFCs will suffer severe thermal shock due to repective cyclic high heat flux (HHF) loads. This paper investigates the effects of thermal shock and damage behavior of tungsten armored PFCs under steady, transient and combined thermal loads. The distribution of stress field is analyzed, and crack initiation is predicted using the extended finite element method (XFEM). The unique features of thermal-mechanical behavior of tungsten armored PFCs under simulated service condition are discussed. The dominant factor of the cracking of the tungsten armor is the brittleness of tungsten below ductile-to-brittle transition temperature (DBTT). Under the steady loads, the cracking position is apt to near the interface of tungsten armor and the interlayer, and the threshold of cracking is between 14 MW/m and 16 MW/m. With 6 MW/m steady loads, applying 1 ms duration of transient load, the cracking threshold is between 0.2 GW/m to 0.4 GW/m. The depth of cracking increases from 100 um to 500 um with the transient load increasing from 0.4 GW/m to 1.0 GW/m. Researches are useful for the design and structural optimization of tungsten-armored PFCs, and the long-term stable operation of further reactor.
聚变能源有望成为下一代替代能源的有力候选者。对于聚变反应堆而言，面对等离子体的部件（PFCs）是实现这一目标的最关键部件。PFCs将由于各自的周期性高热流（HHF）负荷而遭受严重的热冲击。本文研究了钨铠装PFCs在稳态、瞬态和组合热负荷下的热冲击和损伤行为的影响。分析了应力场的分布，并使用扩展有限元法（XFEM）预测了裂纹萌生。讨论了钨铠装PFCs在模拟服役条件下热机械行为的独特特征。钨铠装开裂的主导因素是钨在韧脆转变温度（DBTT）以下的脆性。在稳态负荷下，开裂位置易于靠近钨铠装与中间层的界面，开裂阈值在14MW/m至16MW/m之间。在6MW/m的稳态负荷下，施加1ms持续时间的瞬态负荷，开裂阈值在0.2GW/m至0.4GW/m之间。随着瞬态负荷从0.4GW/m增加到1.0GW/m，开裂深度从100μm增加到500μm。这些研究对于钨铠装PFCs的设计和结构优化以及进一步反应堆的长期稳定运行具有重要意义。
