共查询到20条相似文献,搜索用时 109 毫秒
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介绍了纳米粉体材料的基本制备方法及其技术特点,着重阐述了纳米粉体材料制备中的溶胶-凝胶法、微乳液法、模板合成法和沉淀法的最新研究状况,结合最新的文献论述了纳米粉体材料的几种典型的表征方法,对纳米粉体材料的应用领域及其发展前景进行了总结,并讨论了目前纳米粉体制备技术中存在的问题. 相似文献
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电爆炸方法是制备高纯度纳米粉体材料的新技术,具有能量转化率高、工艺参数调整方便、通用性强的特征。本文分析了电爆炸制备纳米粉体材料的机制,并对近年来国内外在电爆炸法制备纳米粉体材料技术方面的研究进行了评述。在制备非金属纳米材料方面重点阐述了电爆炸法在制备碳纳米材料方面的研究进展,提出了进一步研究的建议。 相似文献
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采用溶胶-凝胶自蔓延法合成锶掺杂铁酸镧粉体,在此基础上制备锶掺杂铁酸镧与钇稳定的氧化锆的复合材料,并研究该材料应用于固体氧化物电解池阳极的各方面性能。通过X射线衍射、透射电镜、扫描电镜等手段,研究该材料的化学稳定性及微观结构。通过动电位扫描研究了该阳极材料的电化学性能。透射电镜分析显示:以该方法制备得到的锶掺杂铁酸镧粉体粒径在20~50nm之间,颗粒形状较为规则。扫描电镜结果显示:经过1200℃、2h的烧结后,复合阳极与电解质结合紧密,阳极材料内部孔隙均匀,钇稳定的氧化锆与锶掺杂铁酸镧两相各自形成连通的网络结构。对锶掺杂铁酸镧-钇稳定的氧化锆阳极复合材料的电化学性能及热循环稳定性进行了研究,结果显示复合阳极表现出较高的电催化活性以及较好的耐热循环稳定性。 相似文献
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利用硅烷偶联剂、醇、油酸钠及自制高分子表面活性剂对锑掺杂二氧化锡纳米粉体(ATO)进行表面处理,研究了不同改性剂对粉体分散性的影响.以改性纳米ATO分散浆料和水性聚氨酯为原料,采用共混法制备了纳米复合涂料,并对其隔热性及基本性能进行测试.TEM及离心实验表明,ATO粉体经自制高分子表面活性剂或硅烷偶联剂改性后,分散性明显提高.性能测试表明:ATO粉体的加入能显著提高涂膜硬度及隔热性. 相似文献
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Suárez G Borodianska H Sakka Y Aglietti EF Vasylkiv O 《Journal of nanoscience and nanotechnology》2010,10(10):6634-6640
A 2.7 mol% yttria stabilizing tetragonal zirconia (2.7Y-TZP) nanopowder was synthesized and stored for five years. Humidity and unsatisfactory storage conditions gradually caused heavy agglomeration. Within a few months, 2.7Y-TZP nanopowder became useless for any technological application. A bead-milling deagglomeration technique was applied to recover the heavily agglomerated yttria-stabilized zirconia nanopowder. Low-temperature sintering and spark plasma sintering (SPS) were performed, resulting in fully dense nanostructured ceramics. Compacts formed with heavily agglomerated powder present low sinterability and poor mechanical properties. Bead-milling suspension formed compacts exhibit mechanical properties in the range of the values reported for nanostructured zirconia. This observation confirms the effectiveness of bead-milling in the deagglomeration of highly agglomerated nanopowders. The high value of Vickers hardness of 13.6 GPa demonstrates the success of the processing technique for recovering long-time-stored oxide nanopowders. 相似文献
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氧化锆前驱体草酸氧锆的制备和表征 总被引:5,自引:1,他引:4
氧化锆膜是目前研究和应用得最多的无机陶瓷膜之一,本文报道了一种制备氧化锆膜前驱体的方法,并用XRD、TGA,DTA和SEM等手段鉴定描述了这各前驱体的粉体特征及其在热处理过程中怕发生的成分,相态变化,实验表明用这种方法制备的草酸氧锆干凝胶具有触变的特性,是制备氧化锆膜的一种经济实用的前驱体。 相似文献
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水热介质pH值对纳米(Ce)ZrO_2晶粒制备的影响 总被引:1,自引:0,他引:1
《中国粉体技术》2000,6(Z1):284-286
用水热法制得纳米 (Ce)ZrO2 粉体 ,其晶粒粒度为 3~ 7nm ,而且为单一分散。用XRD、TEM分析了水热媒介pH值对粒度、m相含量、晶粒形貌的影响关系。结果表明 :水热煤介 pH值增大 ,ZrO2 晶粒也增大 ;pH值减小至酸性时 ,ZrO2 晶粒中出现部分m相 ,且晶粒易团聚 相似文献
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The low temperature aging behavior of polycrystalline tetragonal zirconia was investigated to explore the effects on phase transformation occurring during the process.XRD analysis was conducted for the phase identification and the tetragonal to monoclinic phase transformation was determined.The aging of tetragonal zirconia polycrystals doped with 3 mol% Y2O3 triggers tetragonal to monoclinic phase transformation on the surface of the specimen only,while the penetration inside the bulk of the specimen is very limited.A slight decrease in the mechanical properties was also observed after aging for 40 h.The transformation kinetics show a nucleation and growth mechanism on the specimen surface to be dominant in the low temperature aging in water environment. 相似文献
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Yang Soon-Ho Kim Sang-Bok Kang Bo-An Yun Yeon-Hum Kim Yun-Ho Hwang Kyu-Seog 《Journal of Materials Synthesis and Processing》2001,9(5):275-279
Yttria-stabilized zirconia ceramics are considered to be one of the most important ceramic materials for use in structural applications, because of the high strength and toughness of yttria-stabilized tetragonal zirconia polycrystals. In this work, in order to prepare dense and compact yttria-stabilized tetragonal zirconia body after sintering at 1400°C, we used various raw materials with different particle properties, such as crystallinity, particle size distribution, and particle shape. Crystallinity and tetragonal percentage of the sintered samples were analyzed by X-ray diffraction. Microstructure of the sintered samples was evaluated by field emission-scanning electron microscopy. 相似文献
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Transparent gel monoliths of pure and MgO-doped zirconia having dopant concentrations in the range 0 to 15 mol % were prepared by chemical polymerization of zirconium n-propoxide and magnesium acetate tetrahydrate using 2-methoxy ethanol as solvent. The thermal evolution of amorphous gels was studied by differential thermal analysis, X-ray diffraction and transmission electron microscopy. The crystallization of pure and doped zirconia gels occurred in the temperature range 360 to 450° C. The first crystalline phase to appear is tetragonal for pure and 2 mol % doped zirconia, and cubic for 3 to 15 mol % doped samples. Both crystallization and decomposition temperatures are found to increase with increasing dopant concentration, approaching a saturation value for 10 mol % doped samples. It has been established that the transformation of the cubic to the monoclinic phase takes place via a metastable tetragonal phase. A linear relationship between the lattice parameter of cubic zirconia and MgO concentration has been established. X-ray diffraction studies have also revealed that the entire amount of MgO used in preparing doped zirconia gels remains in a single MgO-ZrO2 crystalline phase formed initially by thermal treatment.[/p] 相似文献
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Inorganic Materials - Raman spectra of zirconia doped with 10, 20, and 25% ytterbia have been measured using light sources with wavelengths of 785 and 532 nm. A number of bands have been shown to... 相似文献