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

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.