共查询到18条相似文献,搜索用时 46 毫秒
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氧化铝泡沫多孔陶瓷的制备 总被引:1,自引:0,他引:1
采用有机泡沫浸渍工艺制备氧化铝泡沫多孔陶瓷。研究了聚丙烯酰胺添加剂对浆料粘度,挂浆成型性能及样品烧后强度的影响,还研究了二次挂浆对氧化铝泡沫多孔陶瓷强度的影响。实验结果表明:当配方组成为氧化铝77.3%、龙岩高岭18.2%、膨润土2.7%、滑石粉1.8%,外加聚丙烯酰胺0.5%,浆料的粘度η0为6.325pa.s,厚化度为1.27,于1600℃,保温2小时烧后样品的强度高。二次挂浆可以显著提高氧化铝泡沫多孔陶瓷强度的影响。对1100℃烧成的样品二次挂浆,在1500℃二次烧成,样品抗弯强度达到3.54MPa。 相似文献
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氧化铝多孔陶瓷制备工艺的研究 总被引:6,自引:0,他引:6
本研究了氧化铝多孔陶瓷的制备工艺,探讨了制备工艺参数对多孔陶瓷性能的影响。研究结果表明,氧化铝骨料颗粒度是得到不同孔径多孔陶瓷的关键;粘结剂含量对多孔陶瓷的孔隙率、强度有很大影响;烧 是得到性能多孔陶瓷的重要因素。通过改变工艺参数,可以得到平均孔径1至10μm,开气孔率40%的氧化铝多孔陶瓷。 相似文献
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采用泡沫浸渍工艺制备出了高孔隙率、高强度的氧化铝多孔陶瓷,研究了泡沫体的预处理方式以及烧成温度对多孔陶瓷性能的影响。扫描电子显微镜(SEM)结果显示:选用聚氨酯泡沫体作为成型骨架,并对其进行酒精浸泡和清水冲洗的预处理过程,最终制备的氧化铝多孔陶瓷具有很高的气孔率,且孔洞分布均匀,孔的连通性好,孔径在0.3-1 mm之间。陶瓷的最佳烧成温度为1600℃,此时陶瓷气孔率保持在67%以上,抗折强度为5.6 MPa。 相似文献
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有机泡沫浸渍法是当前制备多孔陶瓷最为常见的一种工艺,因其可以制备出气孔分布均匀、气孔率超高、贯通且结构为三维立体网络状的多孔陶瓷。本文研究了添加不同种类以及不同含量的分散剂对α-Al2O3在悬浮液中稳定性的影响,结果表明当固含量为5 wt%时,选用阿拉伯树胶分散剂、且添加量为0.8 wt%时,α-Al2O3悬浮液的稳定性最佳。为了有效降低氧化铝陶瓷的烧结温度,通过实验研究选择的助烧剂质量比为2:1的Si O2/Cu O,添加量为3 wt%。使用气孔率分别为75%、80%、95%的有机泡沫模板,在固含量选取为30 wt%的悬浮液中浸渍后干燥,最后在1200℃烧结2 h,分别制备得到了气孔率为65%、72%、93%的多孔氧化铝陶瓷。 相似文献
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以十二烷基苯磺酸钠(SDBS)作为发泡剂,凝胶注模结合发泡法制备多孔氧化铝陶瓷.研究了发泡剂SDBS的添加量对多孔氧化铝陶瓷的气孔率、孔径尺寸及气孔分布和抗弯强度的影响.研究结果表明,在一定范围内随发泡剂SDBS添加量的增加,总气孔率和闭气孔率会有明显的上升趋势,孔径尺寸差异逐渐变小,气孔分布的均匀性逐渐变好.当SDBS的添加量超过1.0wt% 后,气孔率虽然无明显变化,但是样品孔径尺寸及气孔分布的均匀性均变差,样品的抗弯强度随着SDBS用量的增加有明显降低的趋势.当SDBS的添加量为1.0wt% 时,可以制备出闭气孔率为49%,抗弯强度为35 MPa,孔径尺寸及气孔分布均匀的多孔氧化铝陶瓷. 相似文献
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Hertzian Contact Damage in Porous Alumina Ceramics 总被引:2,自引:0,他引:2
Bruno A. Latella Brian H. OConnor Nitin P. Padture Brian R. Lawn 《Journal of the American Ceramic Society》1997,80(4):1027-1031
A study has been made of Hertzian contact damage in porous and dense liquid-phase-sintered aluminas. Indentation stressstrain curves show increasing nonlinearity as the materials become more porous, illustrating an increasing component of "quasi-plasticity" in the contact damage. Observations of the surface and subsurface damage patterns using a bonded-interface sectioning technique reveal a transition in the Hertzian damage process, from classical tension-driven cone cracks in the high-density material, to distributed shear- and compression-driven subsurface damage and deformation in the porous materials. Strength tests on specimens subjected to cyclic indentations reveal a substantially higher susceptibility to fatigue in the most porous structure. 相似文献
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《中国耐火材料》2015,(3)
Significant energy saving effects can be made through the improvement of furnace refractories,especially the thermal insulation refractories. In this study,the preparation and the application of different alumina based porous ceramics were briefly introduced. Alumina based porous ceramics were prepared combined foaming method with gelcasting,sol- gel process or cement curing process. The influences of different preparation methods on the sintering shrinkage, porosity, phase composition, microstructure, compressive strength and thermal conductivity were discussed. Alumina based porous ceramics with relatively high strength and low thermal conductivity could be obtained through the above mentioned methods. Compared with the traditional lining materials,about 40% energy could be saved when they were used as the furnace wall. 相似文献
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SALIL K. ROY 《Journal of the American Ceramic Society》1969,52(10):543-548
A water removal method was used to determine pore sizes in highly porous large-pore-size specimens. The maximum, minimum, and equivalent pore sizes, as well as complete size distributions (number of pores vs pore sizes), were obtained. The results agree with those obtained using a mercury porosimeter. Characterizing parameters such as permeable porosity, labyrinth factor, and structure factor were estimated from the water removal porosimeter data. Electrolytic resistance was measured to determine the tortuosity and inert porosity. A physical meaning of Archie's law which correlates the formation resistivity factor with porosity is also given. Sonic Young's and shear moduli depended on both the porosity and particle sizes. The Young's modulus was linearly related to the modulus of rupture. 相似文献
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多孔氧化铝陶瓷具有耐高温、低热导率等特点,是工业窑炉的隔热保温的首选材料.实验以α-Al2 O3、煅烧铝矾土、苏州土为主要原料,采用物理发泡和注浆成型结合的方法制备了具有高气孔率、低热导率的多孔氧化铝陶瓷样品.通过正交实验确定了发泡剂的最佳配方为SDS添加量为0.5 g·L-1、CTAB添加量为0.3 g·L-1及水质量分数为50wt%.并探究了烧成温度对多孔氧化铝陶瓷样品的物理性能、相组成、热导率的影响,结果表明,经1500℃烧成后的最佳配方样品吸水率为13.71%,气孔率为33.14%,体积密度为2.42 g·cm-3,在300℃下测得热导率为0.83 W·m-1·K-1.本实验制备的多孔氧化铝陶瓷样品的相组成为莫来石和刚玉,由于具有大量的气孔,相同能量下气体激发出的声子数量远少于固体,热导率远远低于固体,导致热导率低. 相似文献
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为了避免金属/陶瓷复合散热片两相共烧,并减小因两相热膨胀系数不同而造成在使用过程中的开裂失效问题,采用水基Al2O3陶瓷浆料在低温下进行多层流延,经定向冷冻、低温干燥及烧结工艺,制备出具有小孔径、直通孔结构的片状Al2O3多孔陶瓷.研究了浆料固体含量和冷冻温度对多孔陶瓷片孔隙率和孔尺寸的影响,观察了孔的微观形貌并测试了其热疲劳性能.结果表明:随着浆料固体含量从30%(质量分数)增加到40%,多孔陶瓷片的孔隙率(体积分数)从62.1%减小至51.4%,随着冷冻温度从-15℃降低至-45℃,多孔陶瓷片孔道尺寸逐渐减小;固体含量为40%、冷冻温度为-45℃的多孔陶瓷片在热疲劳实验中裂纹出现最晚,达到695次,其热疲劳性能最好;多层低温流延法制备的多孔陶瓷片层间孔道相互连通. 相似文献