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尖晶石及高铝—尖晶石浇注料的开发应用 总被引:1,自引:0,他引:1
探讨了我国镁铝尖晶石及高铝-尖晶石(含刚玉-尖晶石及矾土熟料-尖晶石)浇注料的开发应用,阐述了我国没档尖晶石的技术特征和优点以及矾土熟料-尖晶石浇注料研制开发和成功应用的巨大意义,认为:从兼顾技术上和经济上的可行性考虑,尖晶石及高铝-尖晶石浇注料的开发应用已经是呈现了蓬勃发展的大好局面,在推进尖晶石及高铝-尖晶石浇注料的开发应用上,我国的耐火材料工作者正站在开发应用的前列、发挥着具有开拓意义的主导 相似文献
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矾土尖晶石钢包浇注料的研制与应用 总被引:2,自引:0,他引:2
采用特级矾土熟料为骨科,天然出合成的镁铝尖晶石为部分基质,选用新型复合结合剂研制成矾土尖晶石质钢包浇注料.使用结果表明:一次性寿命较传统的铝镁浇注料提高80%以上. 相似文献
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用白刚玉、镁铝尖晶石、电熔镁砂和α-Al2O3微粉,在1 650 ℃烧结3h制备了刚玉-镁铝尖晶石复合材料.按照GBT29971982致密定形耐火制品气孔率和体积密度试验方法和静态坩埚法,并结合X射线衍射、扫描电镜和能谱分析研究了不同组成刚玉-镁铝尖晶石复合材料的常温物理性能、显微结构以及将其应用于精炼铝熔融炉用耐火材料时对高纯度铝的影响.结果表明:在1 650 ℃保温3 h的条件下,试样烧结致密,基质中有镁铝尖晶石生成;所制备的试样中,当α-Al2O3微粉与电熔镁砂的质量比为2∶1时,试样具有较好的室温物理性能,并且对高品质铝液的污染很小. 相似文献
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为了实现水煤浆气化炉炉衬材料的无铬化,研究开发合适的耐火材料代替水煤浆气化炉用高铬砖,以尖晶石骨料及细粉、α-Al_2O_3微粉和轻烧Mg O微粉为原料,于1 600℃保温5 h烧成,制备了φ50 mm×40 mm、内孔为φ25 mm×25 mm的镁铝尖晶石质坩埚试样。采用静态坩埚法,借助XRD、SEM+EDS研究了高温煤熔渣对试样的侵蚀行为。结果表明:1)侵蚀后的镁铝尖晶石材料结构疏松,出现较明显的裂纹,煤熔渣完全渗入试样内部。2)经煤熔渣侵蚀后的镁铝尖晶石材料,物相组成发生变化,除原有的镁铝尖晶石外,还有新物相镁铁铝复合尖晶石相存在。3)煤熔渣对镁铝尖晶石材料的侵蚀机制是物理渗透为主,化学熔蚀为辅。 相似文献
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设计不同的水泥熟料物相组成,以石灰石、重烧氧化镁和铝矾土熟料为原料,于1400℃3h处理后制备了含不同量镁铝尖晶石相的铝酸盐水泥。利用XRD和SEM对不同配比的合成产物的物相及形貌特征进行了分析,并对这种新型铝酸盐水泥浇注料进行了抗压强度的测试。结果表明:含镁铝尖晶石的铝酸盐水泥的主要物相为一铝酸钙(CA)、镁铝尖晶石(MA)和二铝酸钙(CA2),还有少量的硅铝酸二钙(C2AS)和残余刚玉(α-Al2O3);浇注料的强度随MA含量的减小而增大,且随水化时间延长,其强度增进稳定。 相似文献
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以优质矾土熟料和烧结刚玉为骨科及掺合料,加入一定比例的钢纤维,配制成热震稳定性好,耐侵蚀的钢纤维增强高铝浇注料。 相似文献
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Jesse Aaron Miller Ivar E. Reimanis Weiguo Miao Anthony C. Sutorik 《Journal of the American Ceramic Society》2017,100(3):894-900
Precipitation of Al2O3 from nonstoichiometric, dense spinel was examined with the intent to design strengthened transparent ceramics. Powders of magnesium aluminate spinel, MgO·nAl2O3, with compositions n=1 and 2 were uniaxially hot‐pressed at 1873 K, hot isostatically pressed at 2073 K, and heat treated in air or vacuum at 1573 K for 1, 5, 10, 15, and 20 hour. It was observed that precipitation of α‐Al2O3 in n=2 material initiated from the surface and progressed to various depths, with greater depths corresponding to treatments in air. The kinetics are shown to be limited by the diffusion of oxygen through the reacted layer. The results reveal that the environment used to densify spinel has a large influence on the evolution of the two phase microstructure during subsequent heat treatment. 相似文献
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分别以轻烧菱镁矿粉和分析纯MgO粉为镁源,以工业α-Al2O3粉为铝源,按n(MgO):n(Al2O3)=1:1的比例配料,经球磨混合、机压成型后,分别在1 550、1 600和1 650℃保温3 h合成了两种不同镁源的镁铝尖晶石试样,对比检测了两种试样的致密度、强度、物相组成和显微结构的差异。结果表明:1)利用两种不同镁源合成试样的致密度和强度均随合成温度的升高而增大,在合成温度相同时,以轻烧菱镁矿为镁源的试样的致密度和强度较高。2)以轻烧菱镁矿为镁源、1 650℃合成的试样的主晶相为尖晶石,还有少量CA2和CaSiO3,其尖晶石晶体发育较好,八面体形态可辨;以分析纯MgO为镁源、1 650℃合成的试样中只有单相镁铝尖晶石,但尖晶石晶体发育较差,只有少数形成较完整的八面体形态。3)轻烧菱镁矿中SiO2、CaO杂质的存在有利于试样中形成CaO-Al2O3-MgO-SiO2系低熔点相,促进镁铝尖晶石晶体的发育及试样的烧结。 相似文献
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《应用陶瓷进展》2013,112(3):131-134
AbstractRare earth cation segregation in magnesium aluminate spinel has been imaged and analysed in an aberration corrected scanning transmission electron microscope. The SuperSTEM at Daresbury Laboratory provided evidence for monolayer segregation of europium ions along grain boundaries in spinel. EELS spectra confirmed the Eu to be within 0.5 nm of the grain boundary region. Spinel is a candidate material for hard window applications owing to its excellent transparency, intrinsic hardness, fracture toughness and resistance to thermal and chemical erosion. Rare earth cation doped spinel maintains good transparency throughout visible and near infrared wavelengths. 相似文献
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N.A.L. Mansour 《Powder Technology》1977,18(2):127-130
MgAl2O4 was prepared by cocrystallizing and decomposing Al(NO3)3.9H2O and Mg(NO3)2.6H2O mixture. The crystallite growth of the resulting powder was studied in the temperature range 500 – 1000 °C. It was found that the equation governing the process is D2 – D20 = KT. Two activation energies for crystallite growth were obtained, 22 kcal and 44 kcal for the temperature ranges 500 – 785 °C and 785 – 1000 °C respectively. It was noted that rapid increase in crystallite size occurred on soaking at a temperature > 800 °C. 相似文献
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《Journal of the European Ceramic Society》2007,27(11):3339-3344
The mechanical properties and microstructure of alumina-rich magnesium aluminate spinel/tungsten (14 and 22 vol.% W) composites obtained by hot press at 1650 °C under reducing conditions have been investigated. The R-curve for these composites was estimated by the indentation strength method and compared with that of the monolithic spinel obtained under similar conditions. Rising R-curve behavior was specially observed in the composites when tungsten content was higher. Other mechanical properties such as hardness, toughness, Young's modulus and bending strength, were also determined for both (composites and monolithic magnesium aluminate). Higher values of bending strength were found as the metal volume fraction increases in the composite. The metal content dependence of Young's modulus and Vickers hardness follow the rule of mixtures. Mechanical properties and specially toughness are influenced by the metal content and its grain size. 相似文献
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