文摘
B<sub>4sub>C hollow microspheres have been proposed to be a promising target pellet for inertial confinement fusion (ICF). However, the preparation of a B<sub>4sub>C hollow microsphere is challenging and has been rarely reported. In this study, we developed a gel-casting method followed by a calcining process to fabricate a core-shell structured B<sub>4sub>C microsphere on a molybdenum core. The microstructure, stoichiometry, surface roughness, and wall thickness of the microsphere was characterized by Scanning Electron Microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray photography. The results indicated that a core-shell structured microsphere with uniform microstructure and high strength were obtained by gel-casting, accompanied by calcining at 1400 °C. The diameter of the molybdenum core was 2 mm, and the wall thickness was approximately 100–180 µm. It should be noted that the main phase of core-shell structured microsphere was B<sub>4sub>C, with a small amount of residual carbon and B<sub>2sub>O<sub>3sub>. The core-shell structured B<sub>4sub>C microsphere was subsequently processed by laser drilling and corrosion to obtain the B<sub>4sub>C hollow microsphere. It was indicated that the B<sub>4sub>C hollow microsphere has respectable corrosion resistance. Atomic Force Microscope (AFM) analysis demonstrates that the B<sub>4sub>C hollow microsphere exhibits outer and inner surface roughness of 197 nm rms and 19.3 nm rms based on a 5 µm square scan, respectively. This study provides a new method for preparing a high quality B<sub>4sub>C hollow microsphere, which have potential application as a target pellet for ICF.