Li/V包层MHD绝缘涂层的研究现状与展望

Progress and prospect in the development of electrically insulating coatingsfor Li/V self-cooled blanket

摘要:

绝缘涂层是解决液态氚增殖剂包层磁流体动力学(MHD)压降的一种行之有效的方法。本文着重介绍了应用于Li/V自冷系统包层的CaO,Y₂O₃,Er₂O₃和AlN等几种候选绝缘涂层的稳定性研究、制备方法。研究表明,以Er₂O₃、AlN等为代表的若干种候选绝缘材料并没有表现出理论上的稳定性,这使得绝缘涂层的研究重心逐渐从单层绝缘涂层转向了复合绝缘涂层。然而,目前以“钒合金 /绝缘层/金属层”结构为代表的复合绝缘涂层(如“V-alloy/Er₂O₃/V”等)虽表现出了较好的稳定性和足够的绝缘性,但也存在着一些明显的缺点,如无法实现原位制备及原位修复,制备工艺难以应用到大型的具有复杂形状的部件等。未来的工作可以着重设计和制备更有应用潜力的双层或多层绝缘涂层。作者提出了“钒合金/金属/绝缘层”结构的复合绝缘涂层,如“V-alloy/Ti/AlN”,其优点之一就是有潜力可以实现原位制备和原位修复,具有较好的。

Abstract:

Applying an electrically insulating coating on the inner surface of the lithium flowing ducts is a feasible way to effectively mitigate the MHD pressure drop for Li/V self-cooled blanket. This paper mainly overviews the present progress and issues of the insulating coatings, including the single-layer insulator and the multilayer insulatos. Many studies have showed that the single-layer insulator does not perform as stablely as theoretically especially at elevated temperatures, so the necessary of development of the multilayer insulators has been stressed. However, the currently investigated “V-alloy/insulator/metal” structured multilayer insulting coating (such as V-alloy/Er2O3/V) exists some obvious weaknesses, such as the difficulty in realizing the in situ formation and self-healing of the surface metal layer, the compatability problem between lithium and the surface metal layer. Then a new V-alloy/metal/insulator structured multilayer insulator is proposed, which has the potential to realize the in situ formation and self-healing and probably a new possibility for the development of the insulating coating.