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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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氮化硅对注凝成型熔融石英陶瓷性能影响的研究 总被引:1,自引:0,他引:1
以丙烯酰胺(AM)为有机单体,N,N'-亚甲基丙稀酰胺(MBAM)为交联剂,过硫酸铵(APS)为引发剂,pH=3.5,温度为1190 ℃保温5 h的条件下,采用注凝成型方法制备熔融石英陶瓷;以氮化硅为添加剂,通过XRD、SEM等分析不同氮化硅添加量对熔融石英陶瓷的影响,结果表明,氮化硅促进石英陶瓷的烧结,不会导致方石英出现;试样常温抗折强度、体积密度随氮化硅添加量的增加而增大,而显气孔率随氮化硅添加量的增加而减小.当氮化硅添加量为2%时,试样常温抗折强度为37.13 MPa,体积密度为1.96 g/cm3 ,显气孔率为10%. 相似文献
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《中国陶瓷》2019,(7)
采用固相合成法制备0.7CaTiO_3-0.3NdAlO_3微波介质陶瓷,研究添加不同含量的Li_2ZnTi_3O_8,在不同的烧结温度下,对其烧结特性和微波介电性能的影响。结果表明,掺入Li_2ZnTi_3O_8烧结温度降低了150℃;Li_2ZnTi_3O_8不同添加量下,其介电常数随烧结温度升高而增大,但增加不明显;而随着添加量的增加,其介电常数也随之增大。品质因素随着烧结温度升高而升高,随着Li_2ZnTi_3O_8添加量的增大而降低。添加1 wt%Li_2ZnTi_3O_8的陶瓷样品在1400℃烧结,性能最佳,介电常数达到46,品质因素可达到25000 GHz。 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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采用直接起泡法,通过氮化硅颗粒稳定泡沫机制制备氮化硅泡沫陶瓷,研究了烧结温度、保温时间、烧结氮气压、烧结助剂(Al2O3+Y2O3)添加量以及Al2O3与Y2O3质量比对氮化硅泡沫陶瓷中晶须生长的影响,分析了泡沫陶瓷的微观结构。结果表明:通过工艺条件的控制可得到由长柱状β-Si3N4晶粒构成的显微结构;当烧结温度为1750℃、保温时间为4 h、烧结气压为0.9 MPa、烧结助剂添加量为6%(质量分数)、Al2O3与Y2O3质量比为1:1时,β-Si3N4晶粒的长径比达到12以上。 相似文献
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负离子释放材料是一种能够改善污染环境的新型材料。通过将负离子释放材料——电气石加入到陶瓷原料中,制得能够在空气中释放较高负离子浓度的新型陶瓷产品。本文研究了配方、烧结温度和水浸泡对负离子释放量的影响,并利用X射线衍射研究了该陶瓷的晶相结构。 相似文献
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Pengnan Ma Jiankang Wang Hanxiao Meng Laiquan Lv Hao Fang Kefa Cen Hao Zhou 《中国化学工程学报》2022,42(2):415-423
Waste selective catalytic reduction (SCR) catalyst as a hazardous waste has a significant impact on the environment and human health. In present study, a novel technology for thermal treatment of waste SCR catalyst was proposed by adding it to sinter mix for iron ore sintering. The influences of coke rate on the flame front propagation, sinter microstructure, and sinter quality during sintering co-processing the waste SCR catalyst process were studied. In situ tests results indicated the maximum sintering bed temperature increased at higher coke rate, indicating more liquid phase generated and higher airflow resistance. The sintering time was longer and the calculated flame front speed dropped at higher coke rate. Sinter microstructure results found the coalescence and reshaping of bubbles were more fully with increasing coke rate. The porosity dropped from 35.28% to 25.66%, the pore average diameter of large pores decreased from 383.76 μm to 311.43 μm. With increasing coke rate, the sinter indexes of tumbler index, productivity, and yield, increased from 33.2%, 9.2 t·m-2·d-1, 28.9% to 58.0%, 36.0 t·m-2·d-1, 68.9%, respectively. Finally, a comprehensive index was introduced to systematically assess the influence of coke rate on sinter quality, which rose from 100 to 200 when coke rate was increased from 3.5% (mass) to 5.5% (mass). 相似文献
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以某冷却面积为405 m2的环冷机为研究对象,基于多孔介质和局部非热力学平衡理论,建立了环冷机二维稳态数值计算模型。借助COMSOL软件的自定义函数功能,将环冷台车沿运行方向的移动速度定义到数值模型中,研究并分析影响烧结矿余热回收的主要因素及其影响规律。以环冷机出口冷却空气的焓(火用)作为参数优化指标,并采用正交试验设计方法,得出环冷机一二段适宜的操作参数组合。结果表明:当其他操作参数不变时,随着入口风速的增加,出口冷却空气所携带的焓(火用)呈现先增大后减小的趋势。环冷机一二段适宜的操作参数为:冷却空气进口标况流量8.3×105 m3·h-1、料层高度1.6 m和进口风温424 K,此工况下出口热载体焓(火用)值比现有实际工况的提高了11.09%。 相似文献
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以连续性煤气升温模拟高炉生产过程,研究烧结矿的粉化行为,考察了煤气成分对烧结矿低温还原粉化的影响. 结果表明,可将烧结矿在高炉内的低温还原粉化过程分为3个阶段,粉化最剧烈的是第二阶段(400~600℃),此阶段烧结矿粉化指数达50.2%,占整个还原阶段粉化指数的48.5%,还原度却只有15.39%,占整个还原度的17.9%,中值粒径为3.91 mm. 增加还原煤气中的H2比例可增加烧结矿的粉化指数,但增加幅度逐渐降低;增加还原煤气中CO2比例可降低烧结矿的粉化指数,但降低幅度逐渐减小. 相似文献
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Yu. A. Pirogov M. I. Prokopenko L. A. Babkina E. E. Badiyan I. N. Semenenko 《Refractories and Industrial Ceramics》1978,19(3-4):163-167
Conclusions The relation was determined between the sinter adhesion strength and the defectiveness of the structure of MgO powders produced by the thermal decomposition of magnesium compounds. The adhesion strength increases with the level of the microdistortions of the lattice and decreases with the degree of dispersion of the blocks of the substructure. The influence of the defects of the crystal structure on the sinter adhesion strength is at maximum in the first stage of firing.Translated from Ogneupory, No. 3, pp. 33–37, March, 1978. 相似文献
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Sri Lakshmi Katar Dionne Hernandez Azlin Biaggi Labiosa Luis Fonseca Brad Weiner Gerardo Morell 《Electrochimica acta》2010,55(7):2269-2274
A dual stage technique employing hot filament chemical vapor deposition (HFCVD) and radio frequency sputtering was used to synthesize SiN/BCNTs (bamboo like carbon nanotubes) on copper substrates. The films were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Electron field emission studies (EFE), charge-discharge, and cyclic voltammetry. The comprehensive characterization is consistent with a nanolayer of amorphous SiN on BCNTs. Field emission experiments confirm the excellent contact of the SiN nanolayer with the surface of the BCNTs necessary for fabrication of a coin cell. Electrochemical testing shows that SiN/BCNT electrode can deliver an initial discharge capacity of 2000 mAh g−1 which is higher than the capacity of graphite and the reversible capacity after ten cycles is 300 mAh g−1. The cyclic voltammetry results suggest good reversibility with Li during cycling. 相似文献