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采用流延成形法制备AlN陶瓷基片,研究了烧结助剂、烧成温度和保温时间对AlN陶瓷基片烧结性能的影响。结果表明:在烧结助剂(CaF2-YF3)的添加量为4%、烧成温度为1650℃、保温3h,能得到结构致密的AlN陶瓷基片,体积密度达3.25g/c。采用XRD、SEM等检测手段对AlN陶瓷基片的物相和形貌进行了分析,揭示AlN陶瓷基片烧结性能与工艺参数之间的关系。 相似文献
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对比了ZrN+AlN助烧结剂与ZrN+AlN+Y2O3助烧结剂对1800℃、25 MPa下热压烧成Si3N4陶瓷显微结构和力学性能的影响,并着重对ZrN+AlN+Y2O3复合助烧结剂促进Si3N4陶瓷烧结的机理进行了探讨.结果表明加ZrN+AlN+Y2O3助烧结剂能明显促进Si3N4陶瓷的烧结,提高陶瓷强度,其相对密度可达97.84%,常温弯曲强度为601.21 MPa,断裂韧性达8.9 MPa·m1/2;而加ZrN+AlN助烧结剂的Si3N4陶瓷未致密化. 相似文献
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以CaO-B2O3-ZnO-SiO2(CBZS)玻璃粉以及AlN粉体为原料,采用常压烧结法制备了CBZS/AlN玻璃-陶瓷,研究了不同CBZS玻璃含量对复合材料烧结性能、热学性能、介电性能以及力学性能的影响规律.结果表明:CBZS玻璃含量的增加,能有效促进CBZS/AlN玻璃-陶瓷的致密化,可在700~775℃烧结获得致密结构的CBZS/AlN玻璃-陶瓷复合材料;但当CBZS玻璃的含量超过65%后,对玻璃-陶瓷烧结性能的促进作用开始减弱,并恶化了复合材料的热导率与弯曲强度,同时增加其介电损耗.当CBZS玻璃含量为65wt%时,在750℃烧结可获得致密结构的玻璃-陶瓷复合材料,其体积密度为2.87 g·cm-3,热导率为5.31 W/(m·K),介电常数为7.45,介电损耗为0.86×10-3,抗弯强度为209.04Mpa. 相似文献
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采用两组复合烧结助剂Y2O3-CaF2,Y2O3-CaF2-Li2CO3在1600℃烧结AlN陶瓷,对AlN陶瓷烧结密度,热性能和电性能进行了测试,并分析了AlN陶瓷物相变化和微观结构。结果表明,复合烧结助剂在低温下能明显促进AlN陶瓷致密化及晶粒生长发育,尤其是添加3wt%Y2O3-2wt%CaF2作烧结助剂,1600℃常压烧结4h制备了结晶良好,相对密度为98.4%,热导率为133.62W/m.K,同时具有较低相对介电常数的AlN陶瓷。在低温常压条件下制备出性能较高的AlN陶瓷。 相似文献
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以AlN粉体为原料,采用无压烧结,选取二元烧结助剂Dy2O3–CaF2在1 800℃氮气气氛下烧结AlN陶瓷,利用Archimedes排水法、X射线衍射、扫描电子显微镜、激光导热分析仪和万能材料试验机对烧结的AlN陶瓷的密度、热性能和力学性能进行了测试,并对AlN陶瓷的物相变化和微观结构进行了表征。结果表明:添加二元烧结助剂Dy2O3–CaF2可以有效促进AlN陶瓷致密化以及晶粒的生长发育,降低AlN陶瓷的烧结温度,改善AlN陶瓷的导热性能。当添加2.5%(质量分数)Dy2O3+1.5%(质量分数)CaF2在1 800℃氮气气氛下常压烧结2 h时,制备出了晶粒发育良好、结晶良好,相对密度99.6%,热导率169 W/(m·K),同时具有较高的机械强度的AlN陶瓷。 相似文献
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快速烧结技术在节省时间和能源方面的巨大优势使其成为一直以来的研究热点。近几十年来,快速烧结技术(如火花等离子烧结、闪电烧结、选区激光烧结、感应烧结、微波烧结和传统烧结装置中的快速烧结等)的发展,使陶瓷材料的快速烧结成为可能。本文综述了近20年来先进陶瓷领域中的快速烧结技术和烧结机理,并对火花等离子烧结中直流脉冲电流和机械压力对微观结构、材料性能和烧结机理的影响进行了深入分析和总结。同时指出,快速烧结技术今后的发展一方面是对烧结机理的进一步研究并应用到先进陶瓷材料的制备中,另一方面是解决快速烧结技术工业化生产中大尺寸、大批量生产的难题。 相似文献
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Yayun Liu Chuanyang Wang Kedong Zhang 《International Journal of Applied Ceramic Technology》2022,19(4):1904-1915
Al2O3-based green ceramics are prepared by isostatic cold pressing technology. The prepared green ceramics are pre-sintered at the temperature from room temperature to 1100°C, and then Al2O3 ceramics are prepared by laser sintering. The effects of pre-sintering temperatures and laser parameters on mechanical properties and the sintering quality are analyzed. The results show that good crystallinity of Al2O3 particles is obtained at a higher pre-sintering temperature. The flexural strength and density of green ceramics increase with the temperature of heat treatment. The flexural strength decreases slightly at ∼200°C due to the paraffin binder disintegration. The pre-sintering temperature and laser processing parameters have a significant influence on the sintering quality. With the increase of laser power and laser frequency, dynamic grain growth occurs, and then grains are refined. The majority of plate-like grains are transformed into long cylindrical-like grains in the severe densification process. However, porous flocculation microstructures are generated on the samples pre-sintered at 1100°C after laser sintering, which is due to the material gasification in atmospheric environment during sintering by infrared laser. More uniform microstructure and better sintering quality of samples pre-sintered at 500°C can be achieved after laser sintering with a relatively narrower grain size distribution. 相似文献
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以自蔓延高温合成的AIN粉体为原料,Y2O3、Dy2O3、La2O3为添加剂,采用真空热压烧结工艺,实现了含有添加剂的AIN陶瓷体的低温烧结;研究了烧结温度对AIN烧结性能的影响。用XRD、SEM对AIN高压烧结体进行了表征。研究表明:粉体粒径、烧结工艺、烧结助剂对AIN陶瓷低温烧结真空热压烧结性能有很大影响;含烧结助剂的真空热压烧结能够有效降低AIN陶瓷的烧结温度并缩短烧结时间,使烧结体的结构致密。烧结温度1550℃条件下,真空热压烧结90min时,得到的AIN陶瓷的致密度最高。 相似文献
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针对常规烧结制备高含量氧化铝陶瓷均存在烧成温度高的缺点,提出了以掺杂、低温液相烧结结合的方法制备高含量氧化铝陶瓷的方法,并研究了以该方法制备的95瓷微观结构与吸水率、弯曲强度。研究结果表明,掺杂-低温液相烧结的方法可在相同烧成温度下制备出比离子掺杂、低温液相烧结更致密的95瓷,且吸水率小,弯曲强度高于相同温度下采用掺杂和低温液相烧结制备的95瓷。 相似文献
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《Ceramics International》2023,49(12):20298-20303
The development of optoelectronic devices depends on the development of optoelectronic materials such as transparent ceramics. LiF transparent ceramics are photoelectronic ceramics with excellent photoelectric properties. Still, the traditional preparation of LiF transparent ceramics generally needs a high temperature or high-pressure environment, and the cost is high. This paper adopts a cold sintering process to prepare high-density LiF transparent ceramics at low temperatures to reduce the preparation conditions. The effects of different cold sintering temperatures on microstructure, density, hardness, visible and near-infrared transmittance, and electrical properties of transparent ceramics were studied. The results show that using LiOH solution as the solvent, the relative density of LiF ceramics can reach up to 99.64% under the sintering condition of 375 °C/470 MPa, and the Vickers hardness is 1.34 GPa. Vickers hardness is 1.34 GPa. The transmittance in the visible and near-infrared regions is 60.45% and 85.31%, respectively. The dielectric constant and dielectric loss of 13 GHz are 4.36 and 1.11 × 10−3, respectively. 相似文献
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液相烧结氧化铝陶瓷及其烧结动力学分析 总被引:10,自引:3,他引:7
研究了CuO TiO2复相添加剂对Al2O3陶瓷烧结性能、显微结构的影响以及添加剂形成液相时Al2O3陶瓷的烧结动力学.结果显示:添加剂的加入明显地促进了Al2O3陶瓷的烧结致密度.添加剂含量对致密有明显影响,含量越高,烧结速率越快.当添加剂(CuO TiO2)为2%(质量分数),CuO/TiO2质量比为1/2时,Al2O3样品致密度最高.添加剂的存在使Al2O3晶粒发生较快生长,晶粒形貌为等轴状.通过等温烧结动力学,确定掺杂Al2O3陶瓷烧结激活能为25.2kJ/mol,表明可能是氧离子和铝离子在液相中的扩散作用控制了烧结过程. 相似文献
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由不同成型方法,单面或双面加压,制备了氧化锆层状复合陶瓷,研究了制备方法和工艺参数,如:加压压力、时间,对生坯密度的影响.探讨了生坯密度与烧结收缩之间的相关性.研究结果表明:选取成型压力在250 MPa左右,双向加压方式,可以获得沿x,y,z轴方向收缩较一致的层状陶瓷制品.引入评价不同方向的烧结收缩变化参数k(=a/b,a和b分别为沿x,y和z方向的烧结收缩率),kxy,kz,当kxy=kz=1时,表示烧结过程基本完成,坯体中颗粒已达到致密化状态;当kxy-1/kz^2=0或接近于0时,表示沿x,y轴和z轴方向的烧结收缩基本无差别,是一种最佳的层状陶瓷烧结状态. 相似文献
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Eirik Hagen Yingda Yu Tor Grande Ragnvald Høier Mari-Ann Einarsrud 《Journal of the American Ceramic Society》2002,85(12):2971-2976
The densification of aluminum nitride using Ca12 Al14 O33 as a sintering aid has been studied with emphasis on the effect of using coarse or fine powder, the amount of sintering aid, the sintering temperature, and embedding. Both crystalline and amorphous grain boundary phases were observed. Significant weight losses were observed for coarse-grained samples, and if suitable embedding was not used. Porous and coarse-grained ceramics with high contiguity and minor amounts of secondary phases were obtained by enhanced evaporation while dense ceramics were obtained limiting the evaporation. High weight losses in the graphite environment resulted in formation of a dense AlN surface layer. 相似文献
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