多弧离子镀制备的耐事故燃料包壳铬涂层晶粒结构研究

Granular structure of chromium coatings prepared by arc ion plating for accident-tolerant fuel cladding

摘要:

本文通过从几十微米到几埃的多尺度表征展示了多弧离子镀制备铬涂层的详细结构. 经XRD，SEM，FIB，TEM和 HRTEM表征，结果显示该涂层是一种多重结构，包括表面上的微米级颗粒、缺陷带钉扎的微米或次微米级液滴、以堆垛层错为晶界的柱状晶、以刃位错和螺型位错为区分的微晶、位错末端的原子畸变以及原子排列无序化的区域. 这些结构通过改变涂层的结晶度，影响了晶格常数、表面粗化和FIB溅射裂纹. 此外，通过分析HTEM照片，确定了这些堆垛层错和位错的类型. 最后，讨论了沉积参数对这些晶粒结构的影响.

Abstract:

In this paper, the detailed structure of chromium coating prepared by multi-arc ion plating is shown by multi-scale characterization from about tens of microns to several angstroms. Characterized by XRD, SEM, FIB, TEM and HRTEM, the coatings show a multiple configuration including the micron-sized particles on the surface, the micron or submicron-sized droplets pinned by defect bands around, the columnar grains with stacked faults as boundaries, the ambiguous crystallites differentiated with edge and screw dislocations, the atomic distortions on the ends of these dislocations, and some disordered regions. These structures are found to affect the crystal constant, surface coarsening, and FIB-sputtered cracks by changing the coating crystallinity. In addition, the types of stacking faults and dislocations are confirmed by analyzing the HRTEM images. And finally, the effects of depositing parameters on the granular structure are also discussed.