共查询到19条相似文献,搜索用时 93 毫秒
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本文研究了氮化硅加入物对石英陶瓷性能的影响。结果表明,氮化硅有助于石英陶瓷的烧结,而对烧结温度无影响。烧成在1150℃~1200℃温度范围内,石英陶瓷的强度、体积密度随氮化硅的添加量增大和烧结温度提高而增大,而石英陶瓷的显气孔率随氮化硅添加量的增大和烧结温度的升高而减小。 相似文献
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研究了氮化硅加入物对石英陶瓷性能的影响。结果表明,氮化硅有助于石英陶瓷的烧结,而对烧结温度无影响。在1150℃ ̄1200℃的温度范围内,添加0.5 ̄1.5%的氮化硅不会引导石英玻璃的析晶。烧成在1150℃ ̄1200℃温度范围内,石英陶瓷的强度、体积密度随氮化硅的添加量增大和烧结温度提高而增大,而石英陶瓷的显气孔率随氮化硅添加量的增大和烧结温度的升高而减小。 相似文献
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刘大成 《陶瓷研究与职业教育》2000,(4)
分析了二氧化锆的性质及氧空位对二氧化锆相变的影响 ,讨论了二氧化锆韧化氮化硅陶瓷的影响因素 ,提出了二氧化锆韧化氮化硅陶瓷时避免氮化锆生成、促进复相氮化硅陶瓷烧结的途径。 相似文献
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THOMMY EKSTRÖM NILS INGELSTRÖM ROBERT BRAGE MICHAEL HATCHER THOMAS JOHANSSON 《Journal of the American Ceramic Society》1988,71(12):1164-1170
The present work is concerned with the sintering of an α-β sialon ceramic using five different silicon nitride powders from a single source. The parameters varied in the silicon nitride were the amount of "free' silicon, iron content, α:β ratio, and grain size as measured by BET surface. The sintering atmosphere was varied by use of protective powder beds with passive (boron nitride) and active (SiO-generating) properties. Five sintering temperatures between 1600° and 1800°C were used. Microstructural characterization as well as density, hardness, and fracture toughness measurements were carried out. The sintering conditions were found to be critical for obtaining fully dense materials and low weight change. The optimum sintering temperature was 1750°C. The silicon nitride powder with a high content of free silicon resulted in a material which was more susceptible to the sintering atmosphere conditions. An α-β sialon made from a silicon nitride powder with a high β-α phase ratio resulted in a higher β-α ratio in the sintered material. 相似文献
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加入纳米氮化硅对氮化硅陶瓷性能与结构影响 总被引:2,自引:0,他引:2
本文以亚微米级氮化硅为起始原料,加入纳米氮化硅来增强基体,添加氧化铝和氧化钇为烧结助剂,等静压成型,采用无压烧结的方式来制备具有优良性能的氮化硅陶瓷。主要研究了纳米氮化硅的分散;纳米氮化硅的加入量对氮化硅陶瓷力学性能的影响;纳米氮化硅的加入量对氮化硅陶瓷使用性能的影响;纳米氮化硅的加入量对氮化硅陶瓷显微结构的影响。研究结果表明:乙醇作为溶剂在分散介质为聚乙二醇的情况下,超声波震荡40分钟时,纳米氮化硅分散效果最好;随纳米氮化硅加入量的增加,显气孔率增加,吸水率增大;加入3wt%的纳米氮化硅时,试样的体积密度最大,抗弯强度、洛氏硬度、断裂韧性最好,具有较理想的显微结构。 相似文献
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N. F. Gadzyra G. G. Gnesin A. A. Mikhailik 《Refractories and Industrial Ceramics》2001,42(11-12):429-433
The synthesis of a nanocomposite powder of a solid solution of carbon in silicon carbide with controlled content of nitride phases is considered. A method of activated sintering for molding a pore-free nanocomposite ceramic with superior mechanical properties is proposed. Microstructure of the sintered ceramic is examined. 相似文献
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Wenlong Huo Xiaoyan Zhang Jie Xu Zunlan Hu Shu Yan Ke Gan Jinlong Yang 《Journal of the American Ceramic Society》2019,102(5):2245-2250
Three-dimensional ceramic nanofiber-assembled materials with large specific surface area and excellent thermal insulation properties are attracting increasing interests for their unique structure and promising applications. In this paper, we propose a facile methodology to fabricate three-dimensional silicon nitride nanofiber-knitted ceramic foams via in situ reactive synthesis from silicon foams. Silicon particle-stabilized foams are fabricated for the first time using long-chain surfactant cetyltrimethyl ammonium bromide as a hydrophobic modifier. First, the fabrication and stability of silicon foams are investigated. Based on the stable silicon foams, silicon nitride-based nanofiber-knitted ceramic foams are synthesized via in situ reactive sintering in nitrogen atmosphere. The novel ceramic foam materials consist of three-dimensional nanofiber-assembled strut wall and nanofiber-spheres in the pores. The diameter of obtained silicon nitride nanofibers ranges from 15 to 100 nm. The unique nanofiber-knitted foams may have potential applications in specific fields, including catalysis, adsorption, separation, and thermal insulation. 相似文献
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运用晶界工程理论,选择能形成高耐炎度晶界相的Y2O3和La2O3双稀土氧化物为Si3N4陶瓷烧结助剂,材料具有优异的高温强度。第二相碳化硅粒子的引入有效地改善了氮化陶瓷的显微结构和力学性能。以无压烧结工艺制备的高性能α/β-Sialon复相陶瘊等在实际应用中获得良好效果。 相似文献
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本研究采用近净尺寸等静压成型,无压烧结Si3N4工艺成功地制备了同了6105紫油机Si3N4对陶瓷气门材料及制备工艺进行了详细讨论。 相似文献
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《Ceramics International》2020,46(9):12942-12947
The highly porous silica ceramics were fabricated by direct foaming with mixed surfactants and the influence of silicon nitride addition and solid content on the microstructures and properties were investigated. The results showed that silicon nitride can impede the formation of cristobalite and facilitates the sintering of silica ceramics. When the addition of silicon nitride powders reached 15 wt%, the highest compressive strength of silica ceramic foams could be obtained. The porosity of silica ceramic foams was tailored in the range of 84.61%–91.35% by adjusting the solid content, and the compressive strength of the obtained ceramic foams ranged from 5.89 MPa to 0.94 MPa. Sound absorption characteristics of silica ceramics foams were investigated. With the porosity of ceramic foams increased from 84.61% to 91.35%, the sound absorption coefficients in the entire sound wave frequency were enhanced due to the reduction of flow resistances, besides, the sound absorption peak varied from 4200 Hz to 2300 Hz, and became more intense and sharper. 相似文献
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Fine grain α-phase silicon nitride (Si3N4) ceramic powders were produced via carbothermic reduction of colloidal SiO2, which contained pre-mixed additives of sintering aids primarily consisting of oxides such as MgO and Y2O3. The powders that were pre-mixed in the starting reactants were chosen based on the final powder composition and on type and amount of the secondary phases desired for sintering. After synthesizing, powder properties were examined using standard characterization techniques (XRD, SEM, BET, etc). This technique of ceramic synthesis has advantages in providing nitride-based ceramic powders, which contain secondary in situ phases that are distributed as sintering additives. Silicon nitride ceramic powders synthesized using this method might therefore be readily sintered because the homogeneously distributed sintering additives were present in the starting materials. In this work, the processing parameters are described in terms of the synthesis conditions. 相似文献