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烧结助剂对CaO-B2O3-SiO2介电陶瓷结构与性能的影响 总被引:1,自引:0,他引:1
以CaO-B203-Si02(CBS)系微波介质陶瓷为基体材料,采用ZnO和Na2O作为烧结助剂,研究了其微观结构、相组成及介电特性.研究结果表明ZnO在烧结过程中与B2O3及SiO2生成低熔点玻璃相,促进以片状集合体形式存在的CaSiO3晶相合成,显著降低了材料的致密化温度;Na2O虽可促进烧结,但会破坏硅灰石晶体结构,导致微波介电性能显著降低2%(摩尔分数)ZnO取代CaO,在1000℃保温2h,具有较好的微波介电性能εr为5.4.Q·f为22000GHz(测试频率f0为8.5GHz). 相似文献
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ZnO和Na2O对CaO-B2O3-SiO2介电陶瓷结构与性能的影响 总被引:10,自引:0,他引:10
研究了烧结助剂ZnO和Na2 O对CaO -B2 O3 -SiO2 (CBS)系微波介质陶瓷介电性能、相组成及结构特性的影响。烧结助剂ZnO在烧结过程中与B2 O3 及SiO2 生成低熔点玻璃相 ,有效地降低了材料的致密化温度 ,烧结机理为液相烧结。碱金属氧化物Na2 O虽然能够有效降低材料的烧结温度 ,但会破坏硅灰石晶体结构 ,引起材料微波性能显著降低。通过实验 ,制备出了具有优良微波介电性能的陶瓷材料 ,适用于LTCC基板及滤波器等高频微波器件的生产 相似文献
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研究了V2O5对Mg4Nb2O9陶瓷的烧结温度、相结构和微波介电性能的影响.结果表明,添加1%~8%的V2O5,能使该陶瓷的烧结温度降低到1000~1050℃而对其微波介电性能的影响很小,材料的主晶相为有序型刚玉结构的Mg4 Nb2O9,存在Mg4Nb2O6和Mg5Nb4O15杂相而没有检测到V2O5的存在.陶瓷的密度对微波介电性能起着决定性作用,介电常数e1与密度成线性关系(在99.99%的置信限内,其相关系数为0.98252),Q·f值与密度的关系较复杂.添加1%的v2O5,将Mg4Nb2O9陶瓷的烧结温度降低到了1050℃,得到了εr=12.72,Q·f=151040GHz的优异性能. 相似文献
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系统地研究了R2O-Al2O3-B2O3-SiO2系统玻璃对羟基磷灰石(HAP,Hydroxyapatite)的烧结和相转变的影响。其中玻璃组成为Na2O5-12,K2O 7-15,Al2O3 3-5,ZnO 0-5,B2O3 15-25,SiO2 65-75(wt%).结果表明R2O-Al2O3-B2O3-SiO2系统玻璃有较强的促进HAP烧结能力,但在较高温度下会促使HAP分解;合适的添加量为30wt%,烧结温度为1000℃。 相似文献
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减少H2O2干扰测定稳定性ClO2含量的方法 总被引:2,自引:0,他引:2
用碘量法测定稳定性ClO2溶液中的ClO2含量时,当稳定液中过碳酸盐过量,测定结果会偏高.作者提出将待测样酸化后加入稍过量的K2Cr2O7与其中的H2O2反应以消除其影响,再用碘量法测定的新方法.方法操作简便,结果可靠,为较准确地检测含过量过碳酸盐的稳定性ClO2溶液中的ClO2真实含量提供了新的途径. 相似文献
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A. G. Aleksanyan S. K. Dolukhanyan A. G. Akopyan V. M. Beibutyan V. Sh. Shekhtman 《Combustion, Explosion, and Shock Waves》1996,32(6):649-654
Combustion ofTi andZr powders in nitrogen(10–70 atm) with subsequent burn-up of the produced -alloys in hydrogen and alsoTi-Zr powder combustion in anN
2+H2 mixture have been studied. The optimal conditions for producing monophase nitrogen-containing alloys and monophase hydronitrides with high hydrogen concentration have been found. The effect of the second metal(Zr) on the combustion regularities, on an increase in the hydrogen solubility in -alloys, and on the thermal stability of the hydronitrides produced has been elucidated. Hydrogen is shown to behave as a homogenizer in combustion of the above compositions.Translated from Fizika Goreniya i Vzryva, Vol. 32, No. 6, pp. 62–67, November–December 1996. 相似文献
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Na-Ti-Si氧化物Ti元素的化学状态分析 总被引:1,自引:0,他引:1
利用熔融方法制备了Na2O-TiO2-SiO2系统玻璃样品,用IR以及XPS等测试手段对系统玻璃样品结构进行了分析。结果表明:Na2O-SiO2-SiO2系统玻璃中Ti^4 离子可以部分地取代Si^4 离子的位置而以网络形成体的形式参与成玻。此外,通过对该系统玻璃的XPS钛元素的化学状态分析,认为该系统玻璃中Ti^4 离子存在[TiO4],[TiO6]等几种不同的微结构单元,并且随着玻璃中TiO2含量的增加,该系统玻璃中四方双锥结构的[TiO6]与正四面体结构的[TiO4]之比增大。 相似文献
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Li2O-Na2O-K2O-CaO-MgO-Al2O3-SiO2系统乳浊釉的研究 总被引:1,自引:0,他引:1
对Li2O-Na2O-K2O-CaO-MgO-Al2O3-SiO2系统釉进行了较全面的正交试验研究,找到了影响该系统釉乳浊及釉面质量的主次因素,获得了性能良好的乳浊釉及其较优乳浊釉配方. 相似文献
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生产乙炔对电石的要求及乙炔清净 总被引:3,自引:0,他引:3
目前国内外乙炔大部分仍是由电石制得。然而由于工业电石除CaC2 外还含有很多杂质 ,所以生产乙炔不仅要求电石的纯度、粒度 ,还要求水温。一般电石的块度采用 8~ 2 5mm ,发生器温度控制在 85± 5℃ ,乙炔气体中含H2 S、H3 P、NH3 等气体会使氯乙烯合成氯化催化剂活性下降。因此 ,必须对乙炔气体进行清洁。采用次氯酸钠液体的氧化性将乙炔中的杂质氧化成酸性物质而除去。 相似文献
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Using the method of X-ray scattering at large angles, the structure of single-phase glass of the PbO-B2O3-SiO2 and CdO-B2O3-SiO2 systems has been studied. The glass of the two-component PbO-B2O3 and PbO-SiO2 systems of the three-component PbO-B2O3-SiO2 system, containing from 10 to 60 mol % of SiO2 at equal fractions of B2O3 and PbO, and the glass of a number of compositions of the CdO-B2O3-SiO2 system containing from 30 to 60% of CdO are investigated. A change in the prevailing interatomic spacings in the dependence on the glass composition is determined. The boron-oxygen network provides the orderliness in the distribution of ions-modifiers observed at distances on the order of 6 Å. It is found that in contrast to boron-oxygen network, the silicon-oxygen network does not have the ability to order the distribution of the ions-modifiers. 相似文献
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Structural and chemical transformations in the ZrO2-Al2O3 and ZrO2-SiO2 systems containing ZrO2 nanocrystals are examined. It is shown that the presence of zirconia nanoparticles in the oxide mixture retards the processes of crystallization and phase formation. The revealed effect is explained by the space blocking of nucleation in the systems under consideration. 相似文献
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Yu. I. Orlov 《Glass Physics and Chemistry》2002,28(5):281-287
The glass formation in the Na2O–SiO2–H2O system is considered in the framework of the free volume theory of glasses. The boundaries of the glass transition range in the given system are determined from the dependences of the specific volume and the degree of connectivity on the water content in the system. The differences in the structure of hydrated glasses prepared by different methods are revealed. It is demonstrated that the molecular packing coefficients of the structures formed by drying of sodium silicate solutions are smaller than those of glasses prepared by hydration of anhydrous glasses. The densities are determined and the molar volumes are calculated for hydrated glasses in the Na2O–SiO2–H2O system with a water content of 12–23 wt % (33–51 mol %) at a constant molar ratio SiO2 : Na2O = 2.8. The correlation relationship for the partial molar volume of water as a component of hydrated glasses is proposed as a function of the water content in the system. The use of this dependence allows one to calculate the molar volumes (densities) of hydrated glasses with different water contents. 相似文献