| In this dissertation, Ti-based amorphous alloy and diamond particle reinforced Ti-based amorphous composite have been successfully synthesized using spark plasma sintering(SPS) method. On the other hand, two typical nanomaterials, titanate nanobelts and nanosized metal oxides, are obtained in one-pot hydrothermal reaction process by using multiple-component Ti-based amorphous powders as dealloying precursors.Ti-based amorphous alloy powders have been successfully fabricated by argon atomization technology. The powders were characterized by DSC and XRD, and the morphology and microstructure of the powders were also observed. The results showed that most of the powders were amorphous.The amorphous alloy powders and diamond particles were mixed by low energy ball milling method and the mixed parameters were studied in detail. The mixed powders after 6 hours of ball milling were found to have few surface defects and uniform mixed characteristics. Therefore, the obtained parameters were used for the following sintering experiments. When compared with the copper mold casting sample with 3 mm in diameter, the bulk amorphous alloys and their composites with the diameter of 20 mm in size, which overcome the size limitation of such material by conventional casting, were prepared by SPS. The microstructure of these materials was analyzed and the microscopic morphology of the materials was also investigated. The obtained samples had amorphous microstructure and the density of the sintered materials was significantly increased by the diamond reinforced particles. Hardness testing and compressive testing of the samples were carried out respectively. The experimental results showed that the compressive strength of the composite can reach 1.96 GPa, with the hardness of 6.75 GPa and maximum compressive strain of 3.2%. It was of interest to note that the sintered composite exhibited an improved plasticity. The compressive fracture morphology of these materials were observed, and it was found that both the casting and sintered Ti-based amorphous alloys showed brittle fracture characteristics. While the fracture surface of the sintered composite exhibited a certain plastic deformation characteristic, i.e.the strength and plasticity of the amorphous alloy could be enhanced by the diamondparticles using powder metallurgy route.The synthesized titanate nanobelts and nanosized metal oxides were characterized by XRD, and the microstructure of the two materials was observed by scanning electron microscope and transmission electron microscope. The photoelectric properties and adsorption properties of these two samples were studied respectively. The results showed that the titanate nanobelts had excellent ultraviolet light absorption properties and remarkable photoelectric conversion performance under the irradiation of ultraviolet light due to the quantum size effect, higher optical absorption rate and larger surface area of this nano-sized semiconductor material. Furthermore, the nanosized metal oxides exhibited good adsorption ability for Cr(VI) ions in the dark condition. The adsorption process was resulted from the positive surface charge at lower p H value, which could be achieved due to the adsorbed protons and in turn determined the ability of the powder samples to adsorb anions. In particular, it was worth mentioning that the powder adsorbents in this work was more desirable and widely applicable as it overcome the bottleneck encountered with conventional nanosized metal oxide adsorbents, such as the difficulty in separating and recovering in liquid system. |
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