INCO-617 alloy hollow sphere foams with average aperture of about 3 mm and about 0.12 mm wall thickness were fabricated by hollow sphere method.Firstly the wet spheres,which are formed as powder shells from slurry by ...INCO-617 alloy hollow sphere foams with average aperture of about 3 mm and about 0.12 mm wall thickness were fabricated by hollow sphere method.Firstly the wet spheres,which are formed as powder shells from slurry by coating polystyrene balls,were arranged with body-centered cubic(BCC) structure.Subsequently,the sphere stacks were heat-treated in vacuum at 350 ℃ for 40 min to decompose the organic materials,and sintered at different temperatures for different time.The effects of slurry components,sintering temperature and sintering time on the density and porosity of cell wall of hollow sphere foam were studied through Scanning Electron Microscopy.The results show that the densities of INCO-617 alloy hollow sphere foam,increasing with the increase of powder content in slurry,sintering temperature and sintering time,range from 1.112 to 1.216 g·cm-3.Extension of sintering time can reduce the porosity of cell wall,which enhances the compression strength of hollow sphere foam significantly.展开更多
A simple and versatile synthesis method was developed to prepare inorganic multi-metal oxide hollow spheres with tunable compositions. The colloidal nanosheets of layered double hydroxides （LDH） with pre-determined ...A simple and versatile synthesis method was developed to prepare inorganic multi-metal oxide hollow spheres with tunable compositions. The colloidal nanosheets of layered double hydroxides （LDH） with pre-determined compositions were used as precursors for multi-metal oxides and carbon spheres （CSs） prepared by hydrothermal carbonization of glucose were used as hard templates. Electrostatic force drove the positively charged LDH nanosheets to be anchored by the negatively charged CSs once they were mixed, leading to the formation of core-shell structures. Finally, multi-metal oxides with hollow spherical structures were obtained by calcination, These hollow spheres were characterized by X-ray diffraction （XRD）, scanning electron microscope （SEM）, trans- mission electron microscope （TEM） and inductively coupled plasma （ICP）. Results revealed that the as-prepared oxide hollow spheres could exactly inherit the metal-to-metal ratios of initial LDH precursors, which provided an effective way to control the compositions of oxide shells. This strategy was suitable for preparation of a series of oxide hollow spheres from binary to multi-component ones, including MgO/Ak2O3, MgO/Fe3O4, NiO/Al2O3, and ZnO/NiO/Al2O3.展开更多
文摘INCO-617 alloy hollow sphere foams with average aperture of about 3 mm and about 0.12 mm wall thickness were fabricated by hollow sphere method.Firstly the wet spheres,which are formed as powder shells from slurry by coating polystyrene balls,were arranged with body-centered cubic(BCC) structure.Subsequently,the sphere stacks were heat-treated in vacuum at 350 ℃ for 40 min to decompose the organic materials,and sintered at different temperatures for different time.The effects of slurry components,sintering temperature and sintering time on the density and porosity of cell wall of hollow sphere foam were studied through Scanning Electron Microscopy.The results show that the densities of INCO-617 alloy hollow sphere foam,increasing with the increase of powder content in slurry,sintering temperature and sintering time,range from 1.112 to 1.216 g·cm-3.Extension of sintering time can reduce the porosity of cell wall,which enhances the compression strength of hollow sphere foam significantly.
文摘A simple and versatile synthesis method was developed to prepare inorganic multi-metal oxide hollow spheres with tunable compositions. The colloidal nanosheets of layered double hydroxides （LDH） with pre-determined compositions were used as precursors for multi-metal oxides and carbon spheres （CSs） prepared by hydrothermal carbonization of glucose were used as hard templates. Electrostatic force drove the positively charged LDH nanosheets to be anchored by the negatively charged CSs once they were mixed, leading to the formation of core-shell structures. Finally, multi-metal oxides with hollow spherical structures were obtained by calcination, These hollow spheres were characterized by X-ray diffraction （XRD）, scanning electron microscope （SEM）, trans- mission electron microscope （TEM） and inductively coupled plasma （ICP）. Results revealed that the as-prepared oxide hollow spheres could exactly inherit the metal-to-metal ratios of initial LDH precursors, which provided an effective way to control the compositions of oxide shells. This strategy was suitable for preparation of a series of oxide hollow spheres from binary to multi-component ones, including MgO/Ak2O3, MgO/Fe3O4, NiO/Al2O3, and ZnO/NiO/Al2O3.
