共查询到20条相似文献,搜索用时 140 毫秒
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《电子材料与电子技术》2008,(3)
氧化铁-石墨/ABS复合材料制备及电磁屏蔽性能;碳纳米管负载纳米TiO2复合材料的制备及组织结构表征;正交排布碳纤维材料的电磁防护性能研究;电磁波屏蔽复合材料的研究进展;导电聚苯胺/羰基铁粉复合吸收效能的研究. 相似文献
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复合先驱体法制备铅镁锰锑铌系压电陶瓷材料 总被引:1,自引:0,他引:1
采用复合先驱体法制备了Pb(Mg1/3Nb2/3)a(Mn1/3Nb2/3)b(Mn1/3Sb2/3)cZrdTieO3(PMMSN) 铅镁锰锑铌多元系中温烧结压电陶瓷材料。结果表明,相同合成条件下,三组元复合先驱体法和六组元复合先驱体法比四组元复合先驱体法制得样品的钙钛矿相含量更高,在700℃即可得到单纯钙钛矿相材料,且复合先驱体法具有比单一先驱体法(二组元)工艺更加简单、成本更加低廉的优势。性能测试结果表明,三组元复合先驱体法制成样品的性能最佳。1 100℃烧结样品的性能参数:Qm为1 916,kp为0.56,r为1 349,d33为326,tg为0.43?02,可以满足超声马达和压电变压器等应用方面的要求。 相似文献
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湿度的影响是金属氧化物半导体室温气敏材料应用中面临的主要挑战之一。本文通过传统的陶瓷制备工艺,将二氧化锡纳米粉与铂粉混合制备成块状的纳米复合陶瓷。这种块体陶瓷材料在室温50%相对湿度环境下对于较高浓度的氢气具有显著的响应,其对于体积分数1%的氢气响应很好,灵敏度可以达到150。然而它在50%相对湿度的环境下对低浓度氢气的响应仍然会受到很大的抑制。另外,二氧化锡团聚体颗粒也被作为原料用来制备Pt-SnO_2复合纳米陶瓷。在室温以及50%相对湿度环境下,它对体积分数1%的氢气灵敏度高达850,而当相对湿度上升到70%的时候,灵敏度依然能达到450。对于很低浓度的氢气,它也保留着显著的氢敏性能,在50%和70%的相对湿度下,对体积分数为0.04%的氢气灵敏度分别为5和4.1。显然,这种块体陶瓷材料在具备更强的抗湿性能的同时具有更高的灵敏度。微观结构显示这种块体陶瓷材料存在许多团聚体,这种不均匀的微观结构对于抗湿性能的调控具有非常重要的意义。 相似文献
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简单介绍了白光发光二极管(LED)中与荧光转换材料和封装工艺相关的现状和存在问题,重点介绍了烁光特晶科技有限公司研制的新型铝酸镁荧光透明陶瓷材料。采用自制的铝酸镁粉体分别混合自制和市售的荧光粉制备了荧光透明陶瓷,对其加工并替代传统白光LED中的荧光粉层和环氧树脂封装外壳进行了封装测试。由于荧光转换物质在透明陶瓷中均匀分布,解决了传统工艺中荧光粉易沉降的问题,有利于出光的均匀性;陶瓷材料比树脂等有机材料热导率高,加快了散热;同时,荧光陶瓷机械强度高、耐腐蚀、耐磨损,可直接作为封装外壳,简化了封装工艺,可拓展LED的应用范围。 相似文献
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讨论了TE011谐振模式的圆环形介质谐振器的研制过程。固定ZnO添加量为质量分数1.00%,考察了WO3改性剂对(Zr0.8Sn0.2)TiO4微波陶瓷介电性能的影响。当w(WO3)为0.25%时,可得到εr为38.0、Q值大于5800(7GHz)、τf小于2.0×10–6/℃的瓷料。以该瓷料为原料制作谐振器,研究了制作工艺和支撑物高度对谐振器性能的影响。发现采用冷等静压成型工艺所制谐振器的Q值比采用干压成型工艺提高了4%。获得了谐振频率为2200MHz的高Q值、高功率、高稳定性圆环形介质谐振器,完全满足设计要求。 相似文献
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WANGFeng-he LEIWu XIAMing-zhu WANGFeng-yun 《半导体光子学与技术》2003,9(2):119-122
The low resistance PTC ceramic thermistor material with excellent eleectrical properties are successfully fabricated by raw materials at industrial range made in our country on the study of its composition expression and fabrication process by using the addition of Nb,La,Y,Ta,microstructure regulator BN and ASTL phase.The composition and its fabrication method are studied.The relation of electrical properties of the PTC ceramic metaerial to its composition expression and its related electrical properties are discussed. 相似文献
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本文研究了以不同物理化学形态的含结晶水有机酸盐草酸氧钛钡为原料时,对多孔性PTC陶瓷的结构与性能的影响;以及同时以不同结晶水含量的草酸氧钛钡为主原料时,二者分别对同一块多孔性PTC陶瓷的不同结构特征、不同性能特征做出的不同贡献。 相似文献
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粒度对CaO-B_2O_3-SiO_2系LTCC材料性能的影响 总被引:2,自引:1,他引:1
用行星球磨机把相同原料球磨不同时间后,制得了不同粒度的CaO-B2O3-SiO2系用于制造LTCC的粉体材料;采用统一的固相烧结陶瓷工艺过程把LTCC粉体材料制备成陶瓷;研究了粉体粒度对瓷体晶相组成、微观形貌及析晶温度等物理性能的影响。结果表明,粉体粒度减小有助于烧结,但粒度过小会使液相在烧结过程中过早出现并包裹住未及排出的气体,从而导致瓷体结构不致密。最终确定球磨时间为7h,中位径为1.29μm,比表面积为7.344m2/g的粉体有较好的综合性能,用其制得的LTCC εr为6.053,tanδ为2.33。 相似文献
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Claudio Ferraro Esther Garcia‐Tuñon Victoria G. Rocha Suelen Barg Maria Dolores Fariñas Tomas E. Gomez Alvarez‐Arenas Giorgio Sernicola Finn Giuliani Eduardo Saiz 《Advanced functional materials》2016,26(10):1636-1645
The directional freezing of microfiber suspensions is used to assemble highly porous (porosities ranging between 92% and 98%) SiC networks. These networks exhibit a unique hierarchical architecture in which thin layers with honeycomb‐like structure and internal strut length in the order of 1–10 μm in size are aligned with an interlayer spacing ranging between 15 and 50 μm. The resulting structures exhibit strengths (up to 3 MPa) and stiffness (up to 0.3 GPa) that are higher than aerogels of similar density and comparable to other ceramic microlattices fabricated by vapor deposition. Furthermore, this wet processing technique allows the fabrication of large‐size samples that are stable at high temperature, with acoustic impedance that can be manipulated over one order of magnitude (0.03–0.3 MRayl), electrically conductive and with very low thermal conductivity. The approach can be extended to other ceramic materials and opens new opportunities for the fabrication of ultralight structures with unique mechanical and functional properties in practical dimensions. 相似文献
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E. I. Vaganova A. A. Mironenko V. A. Paporkov N. A. Rud A. S. Rudyi A. V. Prokaznikov 《Russian Microelectronics》2011,40(1):31-39
A method of fabrication of nanostructured objects, which increases the efficiency of the photo-electric system used in the
conversion of energy of electromagnetic radiation into electric energy is suggested. The method is based on the formation
of metal nanodots on the basis of the surface layer of porous silicon, which concentrates the energy of electromagnetic radiation
due to localized plasmon modes. 相似文献
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Porous barium titanate (BT) ceramics were fabricated by a freeze-casting technique with kaolinite as a suspending agent, and the effects of the kaolinite content on the microstructure and dielectric properties were investigated. The porous BT ceramics possessed high porosity and a unique two-dimensional pore structure along the freezing direction. The absolute value of the zeta potential and the viscosity of the slurry increased with increasing kaolinite content. The zeta potential plot and viscosity characterization results showed that a stable slurry was obtained when the kaolinite content was 8 wt.%. The porosity was substantially affected by the suspension effect and the fluxing action of the kaolinite. Porosity characterization showed that the porosity of the porous BT ceramic reached a maximum value for 8 wt.% addition of kaolinite. Scanning electron microscopy showed that the porous BT ceramics possessed a multilayered channel structure. The temperature dependence of the permittivity showed that the porous BT ceramics possessed good temperature stability of the dielectric constant. 相似文献
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Andronescu E Voicu G Ficai M Mohora IA Trusca R Ficai A 《Journal of electron microscopy》2011,60(3):253-259
Our purpose was to obtain and characterize some collagen/hydroxyapatite (COLL/HA) hybrid composite materials with desired ceramic properties. The ceramic properties of these materials were achieved by combining two drying methods: controlled air drying at 30°C followed by freeze-drying. Through the function of the air drying times, the materials morphology varies from porous materials (when the materials are freeze-dried) up to dense materials (when the materials are air-dried), while the combined drying allows us to obtain an intermediary morphology. The composite materials intended to be used as bone grafts and in a drug delivery system were characterized by XRD, FTIR, SEM, and also by determining the ceramic properties by using the Arthur method. The ceramic properties of these COLL/HA composite materials vary in large range, for instance the density of the materials varies from 0.06 up to 1.5?g/cm(3) while the porosity varies from 96.5% down to 27.5%. 相似文献