Hu Yuebo

Development on Preparation Technology of Aluminum Foam Sandwich Panels

Abstract Aluminum Foam Sandwich (AFS) panels consist of a highly porous aluminum foam core and metal face sheets. They have been known as a new functional material with many excellent comprehensive properties. AFS panels not only have many excellent properties of aluminum foam materials (extremely low density, efficient capacity of energy dissipation, high specific strength and specific stiffness, acoustic and thermal insulation, high damping, etc.), but also solve the shortcoming of low strength of single aluminum foams, which makes them interesting for a number of practical applications, such as the realization of lightweight structures with a high mechanical strength and a good capacity of energy dissipation under impacts. So far, they have received a considerable attention from a great number of researchers. In this work, the development of the preparation method of AFS panels was reviewed, and the merits and faults of different processes were discussed.

Spectroscopic properties and mechanism of Tm3+/Er3+/Yb3+co-doped oxyfluorogermanate glass ceramics containing BaF2 nanocrystals

Transparent Tm3+/Er3+/Yb3+ co-doped oxyfluorogermanate glass ceramics containing BaF2 nanocrystals are prepared. Under excitation of a 980-nm laser diode (LD), compared with the glass before heat treatment, the Tm3+/Er3+/Yb3+co-doped oxyfluorogermanate glass ceramics can emit intense blue, green and red up-conversion luminescence and Stark-split peaks; X-ray diffraction (XRD) and transmission electron microscope (TEM) results show that BaF2 nanocrystals with an average diameter of 20 nm are precipitated from the glass matrix. Stark splitting of the up-conversion luminescence peaks in the glass ceramics indicates that Tm3+, Er3+ and (or) Yb3+ ions are incorporated into the BaF2 nanocrystals. The up-conversion luminescence intensities of Tm3+, Er3+ and the splitting degree of luminescence peaks in the glass ceramics increase significantly with the increase of heat treat temperature and heat treat time extension. In addition, the possible energy transfer process between rare earth ions and the up-conversion luminescence mechanism are also proposed.

Research Progress on Simulation Modeling of Metal Foams

Abstract The metal foams are a novel kind of structural and functional composite materials, which have attracted a wide attention due to their particular structure and characteristics. In order to promote the research and the application of metal foams, six kinds of simulation models about the metal foams were summed up, including cubic cell model, Gibson-Ashby model, octahedron model, tetrakaidecahedron model, Voronoi model and 3D random spheres model. The structure characteristics of each model were described, and the merits and faults of each model were also analyzed synthetically.