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. In this paper, thin palladium (Pd) membranes, which are supported on alumina nanofiber nonwoven produced by electrospinning method, were prepared by electroless plating method. The influence of different pretreatment methods (iron wire activation) and reducing agent (sodium hypophosphite and hydrazine hydrate) on the structure of Pd membrane were studied. The morphology, surface element and crystal structure of the Pd membrane were investigated by SEM, EDS and XRD. The results showed that the compact Pd membrane was formed on the alumina nanofiber nonwoven when the pretreatment method of iron wire activation was adopted and the reducing agent of sodium hypophosphite was used, which will be applied widely in hydrogen separation area.

SnO2/Al2O3 nanofibers have been fabricated from a suitable inorganic–organic composite solution via a simple electrospinning method and followed by calcination treatment of the electrospun polymer/inorganic composite fibers. The effect of voltage, tip-to-collector distance and calcining temperature on the morphology and crystal structure of nanofibres was investigated by scanning electron microscope (SEM), X-ray photoelectron spectra (XPS) and X-ray diffraction (XRD). The diameter and diameter distribution of nanofibers can be controlled by controlling the electrospinning parameters and the more ideal diameter is 200-350nm. The formation of phase identified by XRD indicated the existence of tetragonal rutile tin oxide crystals and amorphous alumina. This paper provides a new method for the preparation of the SnO2/Al2O3 catalysts for NOX reduction.

Microstructure and mechanical/thermal properties of SiCf/SiC composites additionally reinforced with SiC nanowires were investigated. SiC nanowires could be grown successfully within the SiC fiber preform by a chemical vapor infiltration (CVI) process through a control of the deposition parameters. The incorporation of the SiC nanowires into the fiber perform was clearly shown to be effective in increasing the efficiency of the matrix infiltration, and thus resulted in a higher density in a shorter CVI time. The modification of the pore structure and the reduction of the macro-pores in the composite resulted in higher mechanical and thermal properties than the conventional CVI counterpart. The matrix deposition on both surfaces of the SiC fibers and nanowires induced smaller matrix grains in the nanowire-reinforced composite, and thus a higher hardness and elastic modulus than the conventional one after an ion irradiation.

To estimate the ion-irradiation effect on various types of SiCf/SiC composites, a silicon self-ion irradiation was performed at temperatures of 600 C and 1200 C and at doses of 5 dpa and 20 dpa, respectively. These SiCf/SiC composites were prepared by different processes such as CVI (chemical vapor infiltration), WA-CVI (SiC whisker assisted CVI) and hot-pressing (HP) method. Hardness was measured by a nano-indentation tester and microstructural changes were observed by TEM with SAD(selected area diffraction) technique for the specimens prepared by FIB (Focused Ion Beam) milling. The damage dose was calculated by the SRIM2003 code and then compared with microstructureal observation.

Silicon nitride (Si3N4) ceramics have been considered for various components of nuclear power plants such as mechanical seal of reactor coolant pump (RCP), guide roller for control rod drive mechanism (CRDM), and seal support, etc. Corrosion behavior of Si3N4 ceramics in high-temperature and high-pressure water must be elucidated before they can be considered for components of nuclear power plants. In this study, the corrosion behaviors of Si3N4 ceramics at hydrothermal condition (300°C, 9.0 MPa) were investigated in pure water. The grain-boundary phase was preferentially corroded and the corrosion reaction was controlled by the diffusion of the reactive species and/or products through the corroded layer. Results of this study imply that the variation of sintering aids and/or the control (e.g., crystallization) of the grain-boundary phase are necessary to increase the corrosion resistance of Si3N4 ceramics in high-temperature water.