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[Ceramic Engineering and Science Proceedings] Proceeding of the 42nd International Conference on Advanced Ceramics and Composites (Ceramic Engineering and Science Proceedings Volume 39, Issue 2) || Influences of Laser Condition and Slit Shape on Joinability of Zircaloy-SiC/SiC Composite Tube Joint
摘要： As for the fuel cladding in the light-water reactor, silicon carbide fiber reinforced silicon carbide composite (SiC/SiC composite) is one of the promising candidates as a replacement of zircaloy due to many superiorities, where it is necessary to develop the end-cap seal of SiC/SiC composite cladding. In this research, the caulking method was employed as the method for sealing the end cap of SiC/SiC composite tube by zircaloy tube where the titanium micro-powder was inserted between two tubes. The diode or fiber laser was circumferentially irradiated on the outer surface of zircaloy tube, and the insert method of titanium powder was varied by changing the cutting method of SiC/SiC composite tube. The results using the diode laser irradiations with the screw cutting indicated that the wider width of irradiation line seems to be inadequate because the shrinkage of zircaloy would break the thread of SiC/SiC composite. In addition, the examinations about the slit shape effect for the flat cutting suggested that the hook slit is considered to be the best cutting method for holding the titanium powder during the laser irradiation where the width of slit should be narrower than that of laser irradiation line.
关键词： SiC/SiC composite,titanium micro-powder,caulking method,laser irradiation,zircaloy
更新于2025-09-23 15:21:01
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The Effects of Laser Parameters and the Ablation Mechanism in Laser Ablation of C/SiC Composite
摘要： The e?ects of laser parameters and the ablation mechanism in laser ablation of a carbon ?ber reinforced silicon carbide (C/SiC) composite are investigated in the present study. Six di?erent power densities are provided, as well as six levels of pulse numbers, and then ablation experiments are conducted for the C/SiC composite, induced by a pulsed laser. Based on the experimental results, the characteristics of surface morphology and ablation behavior are discussed. It is revealed that the surface morphology of the C/SiC composite under laser irradiation usually includes three regions: the center region, the transition region, and the border region. With the increase of laser power density, the ablation of the center region becomes severe, surface cracks occur, and more spherical SiC particles are found in the transition region. As for scenarios involving multiple pulses, the damage occurs in the center region at low power density limits, within the ?rst two layers below the surface. However, if the power density is relatively high, an ablation pit occurs in the center region when the pulse number is larger than 50. Meanwhile, the transition region and the border region diminish with increase of the pulse number. It is noted that both the power density and pulse number have noticeable e?ects on surface morphology and ablation behavior during laser ablation, which is helpful for material design and performance evaluation of C/SiC composites.
关键词： Surface morphology,C/SiC composite,Ablation mechanism,Laser ablation,Scanning electron microscopy (SEM)
更新于2025-09-12 10:27:22
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Alveolar TiO2-β-SiC photocatalytic composite foams with tunable properties for water treatment
摘要： New alveolar TiO2-β-SiC photocatalytic composite foams gathering within a ready-to-use media, the TiO2 active phase and the β-SiC alveolar foam structure have been prepared through a Shape Memory Synthesis (SMS) replica method. They have been obtained by incorporating TiO2 powders inside the infiltration slurry used for transforming the pre-shaped polyurethane foam into its corresponding carbide. The photocatalytic composite foams contained 16 wt. % and 24 wt. % of TiO2, most of them being available for the reaction by being located in the external layer of the foam rather than dispersed within the foam matrix, so that no further post-synthesis immobilization process was needed for coating the foam with TiO2 active phase. The adsorption behaviour of the TiO2-β-SiC composite foams towards the Diuron pollutant in water was tuned by applying a final calcination treatment to the as-synthesized foams within the 400-700 °C range, that allowed to tune the amount of residual unreacted carbon within the foams, while allowing the formation of small TiO2 crystallites via the selective oxidation of TiC carbide, and thanks to the β-SiC resistance to oxidation. The TiO2-β-SiC composite foams calcined at 700 °C outperformed a reference β-SiC supported foam TiO2 catalyst in terms of diuron degradation, while the reference foam remained more efficient in terms of mineralization rate.
关键词： water treatment,photocatalysis,Shape Memory Synthesis replica method,adsorption properties,TiO2-β-SiC composite foam
更新于2025-09-10 09:29:36