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Interface characteristics of Al_2O_3-13%TiO_2 ceramic coatings prepared by laser cladding 被引量:3
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作者 高雪松 田宗军 +1 位作者 刘志东 沈理达 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第10期2498-2503,共6页
Al2O3-13%TiO2 (mass fraction) coatings, prepared by laser cladding on nickel-based alloy, were heated using high frequency induction sources. The coating microstructure and the interface between bond coating and cer... Al2O3-13%TiO2 (mass fraction) coatings, prepared by laser cladding on nickel-based alloy, were heated using high frequency induction sources. The coating microstructure and the interface between bond coating and ceramic coating were characterized by SEM, XRD and EDS. The results show that two-layer substructure exists in the ceramic coating: one layer evolving from fully melted region where the sintered grains grow fully; another layer resembling the liquid-phase-sintered structure consisting of three-dimensional net where the melted Al2O3 particles are embedded in the TiO2-rich matrix. The mechanism of the two-layer substructure formation is also explained in terms of the melting and flattening behavior of the powders during laser cladding processing. The spinel compounds NiAl2O4 and acicular compounds Cr2O3 are discovered in the interface between bond coating and ceramic coating. It proves that the chemical reactions in the laser cladding process will significantly enhance the coating adhesion. 展开更多
关键词 ceramic coating nickel alloy laser cladding al2o3-Tio2 high frequency induction
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Effects of Yttrium Ion on Formation Mechanism of ZrO_2-Y_2O_3 Ceramic Coatings Formed by Plasma Electrolytic Oxidation on Al-12Si Alloy 被引量:3
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作者 王萍 LI Jianping +2 位作者 GUO Yongchun YANG Zhong WANG Jianli 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2014年第5期1044-1048,共5页
ZrO2-Y2O3 ceramic coating was produced by plasma electrolytic oxidation (PEO) on ZAlSil2Cu3Ni2 alloy. The microstructure and phase composition of the coating were investigated by SEM and XRD.: The results show that... ZrO2-Y2O3 ceramic coating was produced by plasma electrolytic oxidation (PEO) on ZAlSil2Cu3Ni2 alloy. The microstructure and phase composition of the coating were investigated by SEM and XRD.: The results show that adding an appropriate amount of yttrium ion can improve the growing rate of ceramic coating at different oxidation stages and decrease arc voltage. The thickness of ZrO2-Y2O3 coating is 16 μn thicker than that of ZrO2 coating and the maximum oxidation rate improves by 0.6 μm/min. In addition, the arc voltage decreases from 227 to 172 V. It can be seen that the rate of oxidation firstly increases to some extent and then decreases with the content of yttrium ion increasing. The growth rate reaches the maximum while the content of yttrium ion is 0.05 g-L-1The maximum thickness is 90 μm.Compared to ZrO2 coating, the micropores of ZrO2-Y2O3 coating are less and the ceramic layer is repeatedly deposited by ZrO2 and Y2O3 ceramic particles. Meanwhile, the binding force between coating and substrate is better and the coating is uniform and compact. The ceramic layer is mainly composed of c-Y0.15Zr0.85O1.93□0.07, m-ZrO2, α-Al2O3, ,γ-Al2O3 and Y2O3. It is indicated that ZrO2 has beert fully stabilized by yttrium ion through the formation of solid solution. 展开更多
关键词 al-12Si alloys yttrium ion plasma electrolytic oxidation zro2-Y2o3 ceramic coating
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Effect of Nano-ZrO_2 on Microstructure and Thermal Shock Behaviour of Al_2O_3/SiC Composite Ceramics Used in Solar Thermal Power 被引量:2
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作者 徐晓虹 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2011年第2期285-289,共5页
The Al2O3-ZrO2(3Y)-SiC composite ceramics used in solar thermal power were prepared by micrometric Al2O3,nano-ZrO2 and SiC powders under the condition of pressureless sintering.The bulk density and bending strength ... The Al2O3-ZrO2(3Y)-SiC composite ceramics used in solar thermal power were prepared by micrometric Al2O3,nano-ZrO2 and SiC powders under the condition of pressureless sintering.The bulk density and bending strength of samples with 10vol% nano-ZrO2 sintered at 1480℃ were 3.222 g/cm3 and 160.4MPa,respectively.The bending strength of samples after 7 times thermal shock tests (quenching from 1000℃ to 25℃ in air medium) is 132.0MPa,loss rate of bending strength is only 17%.The effect of nano-ZrO2 content on the microstructure and performance of Al2O3-ZrO2(3Y)-SiC composite ceramic was investigated.The experimental results show that the bending strength of samples with above 10vol% nano-ZrO2 content has decreased,because the volume expansion resulting from t-ZrO2 to m-ZrO2 phase transformation is excessive;Adding proper nano-ZrO2 would be contributed to improve the thermal shock resistance of the composite ceramics.The Al2O3-ZrO2(3Y)-SiC composite ceramic has promising potential application in solar thermal power. 展开更多
关键词 al2o3 NANo-zro2 transformation toughening thermal shock resistance composite ceramics solar thermal power
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A novel technique for making open-cell Al_2O_3-ZrO_2 ceramic foam with plant seed template 被引量:2
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作者 Yu Jingyuan Li Qiang +2 位作者 Tang Ji Sun Xudong Li Xiaodong 《China Foundry》 SCIE CAS 2010年第3期224-229,共6页
The aim of the present research is to provide a technique for preparing open-cell Al2O3-ZrO2 ceramic foams with uniform cell size.This technique used plant seeds to array templates and centrifugal slip casting to obta... The aim of the present research is to provide a technique for preparing open-cell Al2O3-ZrO2 ceramic foams with uniform cell size.This technique used plant seeds to array templates and centrifugal slip casting to obtain cell struts with high packing density.Aqueous Al2O3-ZrO2 slurries with up to 50 vol.% solid contents were prepared and the rheological characteristic of the slurries was investigated.Consolidation was performed at an acceleration of 2,860 g for 60 min.The effect of the characteristic of plant seeds on the drying behavior of Al2O3-ZrO2 green compact was analyzed.The effects of the solid contents of slurries on segregation phenomena of Al2O3 and ZrO2 particles and green compact uniformity were investigated.The compressive stress-strain curve and deformation behavior of Al2O3-ZrO2 ceramic foams prepared using plant seed template were analyzed.The results showed segregation phenomenon is negligible for highly stable slurry with 50 vol.% solid loading.The prepared cell struts of Al2O3-ZrO2 foams have high green density (61.9% TD), sintered density (99.1% TD) and homogeneous microstructure.When sintered at 1,550 ℃ for 2 h, the cell size of Al2O3-ZrO2 foam is approximately uniform and the diameter is about 1.1 mm.The porosity and compressive strength of sintered products is 66.2% and 5.86 MPa, respectively. 展开更多
关键词 al2o3-zro2 ceramic foam plant seed template centrifugal slip casting SEGREGATIoN
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Predicting model on ultimate compressive strength of Al_2O_3-ZrO_2 ceramic foam filter based on BP neural network 被引量:1
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作者 Yu Jingyuan Li Qiang +1 位作者 Tang Ji Sun Xudong 《China Foundry》 SCIE CAS 2011年第3期286-289,共4页
In present study, BP neural network model was proposed for the prediction of ultimate compressive strength of Al2O3-ZrO2 ceramic foam filter prepared by centrifugal slip casting. The inputs of the BP neural network mo... In present study, BP neural network model was proposed for the prediction of ultimate compressive strength of Al2O3-ZrO2 ceramic foam filter prepared by centrifugal slip casting. The inputs of the BP neural network model were the applied load on the epispastic polystyrene template (F), centrifugal acceleration (v) and sintering temperature (T), while the only output was the ultimate compressive strength ((7). According to the registered BP model, the effects of F, v, T on 0 were analyzed. The predicted results agree with the actual data within reasonable experimental error, indicating that the BP model is practically a very useful tool in property prediction and process parameter design of the Al2O3-ZrO2 ceramic foam filter prepared by centrifugal slip casting. 展开更多
关键词 al2o3-zro2 ceramic foam centrifugal slip casting BP neural network process parameters ultimate compressive strength
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Preparation of Al_2O_3-SiO_2-TiO_2-ZrO_2 Composite Ceramic Membranes by Sol-Gel Method
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作者 吴建锋 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2005年第1期42-45,共4页
Al 2O 3-SiO 2-TiO 2-ZrO 2 supported membranes were prepar ed by Sol-Gel method. These composite ceramic membranes are level, even and no macro crack. There exist several crystalline phases such as Al 2O 3, TiO... Al 2O 3-SiO 2-TiO 2-ZrO 2 supported membranes were prepar ed by Sol-Gel method. These composite ceramic membranes are level, even and no macro crack. There exist several crystalline phases such as Al 2O 3, TiO 2(a natase), Al 2SiO 5, and ZrO 2 in these membranes. Changing the molar ratio of Al∶Si∶Ti∶Zr,the kinds and content of crystal phases of composite membranes could be different, which may lead to a variety of microstructure of membranes. The surface nanoscale topography and microstructure of membranes were investiga ted by XRD,SEM,AFM,EPMA. The effects of additives and heat treatments on the sur face nanoscale topography and microstructure of composite ceramic membranes were also analyzed. 展开更多
关键词 sol-gel method al 2o 3-Sio 2-Tio 2-zro 2 composite ceramic membranes surface nanoscale topography microstructure
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Microstructure and Grain Boundary Character of Al2O3—Mullite—ZrO2—SiC Ceramic Compostie
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作者 GEHua LITing-shou 《China's Refractories》 CAS 1995年第3期12-18,共7页
Microstructure and grain boundary character of hot pressed binary Al2O3(mullite,ZrO2)-SiC omposites and quaternary Al2O3-mullite-ZrO2-SiC composite were studied by electron microscopy and microanalysis,Results sugges... Microstructure and grain boundary character of hot pressed binary Al2O3(mullite,ZrO2)-SiC omposites and quaternary Al2O3-mullite-ZrO2-SiC composite were studied by electron microscopy and microanalysis,Results suggest that there exist grain boundary solid solutions due to elemental diffusion near SiC and matrix oxides grain boundaries. 展开更多
关键词 微观结构 氧化铝 al2o3 zro2 碳化硅 氧化锆 莫来石 富铝红柱石 晶粒边界 陶瓷复合材料
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Preparation of Crack-free 3Y-TZP/Al_2O_3 Composite Ceramic Fiber by Electrolysis-sol-gel Method 被引量:7
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作者 LI Jian-jun JIAO Xiu-ling CHEN Dai-rong 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2007年第4期377-380,共4页
Polycrystalline 3Y-TZP/Al2O3 tetragonal zirconia fiber was obtained by the pyrolysis of gel fibers using zirconium oxychloride octahydrate(ZOC) as the raw material. The spinnable zirconia sol was prepared by electro... Polycrystalline 3Y-TZP/Al2O3 tetragonal zirconia fiber was obtained by the pyrolysis of gel fibers using zirconium oxychloride octahydrate(ZOC) as the raw material. The spinnable zirconia sol was prepared by electrolyzing the zirco-nium oxychloride octahydrate(ZOC) solution in the presence of acetic acid and sugar( sucrose, glucrose or fructose) , in which the molar ratios of CH3 COOH/ZOC and sugar/ZOC were 1.0-4.0 and 0.2-0.4, respectively. The pre- pared tetragonal zireonia fibers sintered at different temperatures showed smooth and crack-free surfaces with diame, ters of 5-10 μm. The addition of Al2O3 enhanced the sintering process and prevented the crystals from growing. Thermogravimetric analysis(TG), X-ray diffraction ( XRD ), Fourier transform infrared spectroscopy(FTIR), and scanning electron microscope(SEM) techniques were used to characterize the prepared fibers. 展开更多
关键词 ELECTRoLYSIS Sol-gel ZIRCoNIA ceramic fiber al2o3
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浆态床中Cu/ZnO/Al_2O_3/ZrO_2+γ-Al_2O_3双功能催化剂一步法合成二甲醚 被引量:14
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作者 左宜赞 张强 +4 位作者 安欣 韩明汉 王铁锋 王金福 金涌 《燃料化学学报》 EI CAS CSCD 北大核心 2010年第1期102-107,共6页
采用共沉淀法,制备了纤维状CD501甲醇合成催化剂,采用SEM、TEM、XRD和BET等手段对催化剂进行了表征;并将其进一步和γ-Al2O3进行混合,获得了Cu/ZnO/Al2O3/ZrO2+γ-Al2O3双功能催化剂,考察了其在浆态床中一步法合成二甲醚过程的催化特性... 采用共沉淀法,制备了纤维状CD501甲醇合成催化剂,采用SEM、TEM、XRD和BET等手段对催化剂进行了表征;并将其进一步和γ-Al2O3进行混合,获得了Cu/ZnO/Al2O3/ZrO2+γ-Al2O3双功能催化剂,考察了其在浆态床中一步法合成二甲醚过程的催化特性。结果表明,相比商业催化剂(COM)和LP201催化剂,新型的CD501催化剂具有更大的比表面积和Cu/Zn分散性。对于浆态床中一步法合成二甲醚过程,采用CD501与γ-Al2O3双功能催化剂,相比采用COM或LP201与γ-Al2O3双功能催化剂,CO转化率提高了一倍,且经过270 h测试,CO转化率从61%降至57%,二甲醚时空产率从0.54 g/(g.h)降至0.48 g/(g.h),稳定性显著优于COM催化剂。当反应温度为250℃,压力为4.0 MPa,空速为3 000 mL/(g.h),氢碳比为1.0时,该催化剂应用在浆态床一步法合成二甲醚时,CO转化率为61%,DME时空产率达到0.54 g/(g.h)。 展开更多
关键词 Cu/Zno/al2o3/zro2催化剂 al2o3 浆态床 二甲醚 甲醇
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ZrO_2—Al_2O_3复相陶瓷的研究 被引量:16
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作者 高翔 丘泰 +1 位作者 焦宝祥 沈春英 《中国陶瓷》 CAS CSCD 2004年第3期9-13,共5页
以纳米ZrO 、微米Al O 为原料,采用无压烧结方式制备了ZTA 复相陶瓷。结果表明:nano-ZrO 的 2 2 3 2加入有利于制备细晶ZTA 复相陶瓷。此外,nano-ZrO 的加入对 Al O 陶瓷的显微结构也产生影响,ZrO ... 以纳米ZrO 、微米Al O 为原料,采用无压烧结方式制备了ZTA 复相陶瓷。结果表明:nano-ZrO 的 2 2 3 2加入有利于制备细晶ZTA 复相陶瓷。此外,nano-ZrO 的加入对 Al O 陶瓷的显微结构也产生影响,ZrO 颗粒以 2 2 3 2“晶内型”和晶界型两种形式存在。合理的配方组成及制备工艺有利于 Z r O 以四方亚稳相存在。Z r O 含量为 2 23 0 w t % 时,其四方相含量可达 6 9 %,有利于应力诱导相变增韧,该 Z T A 复相陶瓷的抗弯强度、断裂韧性分别达到 604MPa、6.87MPa·m1/2。 展开更多
关键词 纳米zro2 复相陶瓷 ZTA 力学性能 al2o3陶瓷
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ZrO2在β"─Al2O3复合陶瓷中的作用 被引量:7
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作者 温兆银 林祖镶 +2 位作者 顾中华 陈昆刚 樊增钊 《复合材料学报》 EI CAS CSCD 北大核心 1996年第3期38-42,共5页
本文研究了四方和立方ZrO2在与Na-β"-Al2O3的复合陶瓷中作为第二相所起的各种作用。结果说明ZrO2对复合陶瓷具有细化晶粒、改善显微结构、提高强度和断裂韧性的作用,与此同时也在一定程度上降低离子电导率。在提高... 本文研究了四方和立方ZrO2在与Na-β"-Al2O3的复合陶瓷中作为第二相所起的各种作用。结果说明ZrO2对复合陶瓷具有细化晶粒、改善显微结构、提高强度和断裂韧性的作用,与此同时也在一定程度上降低离子电导率。在提高力学性能方面,四方ZrO2除了具有与立方ZrO2相同的弥散颗粒的作用外,相变所起的作用也是很显著的。ZrO2-Na-β"-Al2O3复合陶瓷是一种有应用价值的固体电解质材料。 展开更多
关键词 zro2 al2o3 复合陶瓷
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催化精馏专用填料型固体酸SO_4^(2-)/ZrO_2-Al_2O_3-Al的研究 被引量:12
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作者 杜长海 秦永宁 +2 位作者 贺岩峰 马智 吴树新 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2003年第6期504-508,共5页
为了研制催化精馏专用催化剂 ,采用铝阳极氧化法制备了Al2 O3 Al一体型载体 ,并将活性固体超强酸SO42 -/ZrO2 引入到Al2 O3 Al上 ,得到一种新型催化精馏专用填料式固体酸SO42 -/ZrO2 Al2 O3 Al催化剂 .利用XRD、SEM、BET、XPS、NH3 ... 为了研制催化精馏专用催化剂 ,采用铝阳极氧化法制备了Al2 O3 Al一体型载体 ,并将活性固体超强酸SO42 -/ZrO2 引入到Al2 O3 Al上 ,得到一种新型催化精馏专用填料式固体酸SO42 -/ZrO2 Al2 O3 Al催化剂 .利用XRD、SEM、BET、XPS、NH3 TPD等手段对其进行了表征 .结果表明 ,所制得的阳极氧化铝膜厚为 5 6 μm ,SO42 -/ZrO2 Al2 O3 Al固体酸具有比表面积大、酸强度适中的特点 .XRD结果表明 ,ZrO2 在Al2 O3 Al上处于高度分散状态 .将该固体酸用于乙酸 /乙醇酯化反应中 ,显示出较高的催化活性 。 展开更多
关键词 So4^2-/zro2 阳极氧化 al2o3-al 填料型固体酸 催化精馏 催化剂
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Thermal shock fatigue behavior of TiC/Al_2O_3 composite ceramics 被引量:6
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作者 SI Tingzhi LIU Ning +1 位作者 ZHANG Qing' an YOU Xianqing 《Rare Metals》 SCIE EI CAS CSCD 2008年第3期308-314,共7页
The thermal shock fatigue behaviors of pure hot-pressed alumina and 30 wt.% TiC/Al2O3 composites were studied. The effect of TiC and Al2O3 starting particle size on the mechanical properties of the composites was disc... The thermal shock fatigue behaviors of pure hot-pressed alumina and 30 wt.% TiC/Al2O3 composites were studied. The effect of TiC and Al2O3 starting particle size on the mechanical properties of the composites was discussed. Indentation-quench test was conducted to evaluate the effect of thermal fatigue temperature difference (ΔT) and number of thermal cycles (Ⅳ) on fatigue crack growth (Δa). The mechanical properties and thermal fatigue resistance of TiC/Al203 composites are remarkably improved by the addition of TiC. The thermal shock fatigue of monolithic alumina and TiC/Al2O3 composites is due to a "true" cycling effect (thermal fatigue). Crack deflection and bridging are the predominant reasons for the improvement of thermal shock fatigue resistance of the composites. 展开更多
关键词 ceramic matrix composites TiC/al2o3 composites thermal shock fatigue fatigue behavior fatigue resistance
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Al含量对Pt-S_2O_8^(2-)/ZrO_2-Al_2O_3型固体超强酸催化剂异构化性能的影响 被引量:19
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作者 宋华 董鹏飞 张旭 《高等学校化学学报》 SCIE EI CAS CSCD 北大核心 2010年第7期1426-1430,共5页
通过向S2O82-/ZrO2催化剂中同时引入适量的Pt和Al2O3,制备出了具有较高催化性能和高稳定性的Pt-S2O82-/ZrO2-Al2O3型固体超强酸催化剂.以正戊烷异构化反应为探针,考察了Al含量对催化剂的异构化性能的影响,并采用XRD,BET,FTIR,TPR,TG-DTA... 通过向S2O82-/ZrO2催化剂中同时引入适量的Pt和Al2O3,制备出了具有较高催化性能和高稳定性的Pt-S2O82-/ZrO2-Al2O3型固体超强酸催化剂.以正戊烷异构化反应为探针,考察了Al含量对催化剂的异构化性能的影响,并采用XRD,BET,FTIR,TPR,TG-DTA,NH3-TPD和ICP手段对催化剂进行了表征.结果表明,Al能够延迟ZrO2的晶化温度,抑制硫的分解;Al能够增加催化剂的比表面积,增强硫氧键的结合,提高催化剂的还原性能,增加催化剂的酸强度和酸总量.当Al2O3质量分数为2.5%时,Pt-S2O82-/ZrO2-Al2O3固体超强酸催化剂的催化活性最高,正戊烷异构化收率可达60.02%,选择性在98.2%以上. 展开更多
关键词 固体超强酸 催化剂 S2o28-/zro2 异构化 al2o3含量
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共沉淀法制备ZrO_2-Al_2O_3纳米复合氧化物的物相表征 被引量:27
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作者 梁健 黄惠忠 谢有畅 《物理化学学报》 SCIE CAS CSCD 北大核心 2003年第1期30-34,共5页
用Al(NO3)3和ZrO(NO3)2混合溶液,加氨水共沉淀制备了一系列Al2O3含量由低到高的ZrO2-Al2O3复合氧化物,用XRD、XPS、BET等实验手段对其进行了表征.结果表明,随着一种组分含量由低到高,其主要存在形式按形成固溶体-表面单层分散-析出单独... 用Al(NO3)3和ZrO(NO3)2混合溶液,加氨水共沉淀制备了一系列Al2O3含量由低到高的ZrO2-Al2O3复合氧化物,用XRD、XPS、BET等实验手段对其进行了表征.结果表明,随着一种组分含量由低到高,其主要存在形式按形成固溶体-表面单层分散-析出单独晶相的规律变化,而一种组分的加入均使另一种组分的XRD衍射峰明显宽化,晶粒变细;复合氧化物的比表面明显大于两种组分纯样品比表面的简单加和.实验表明体系中两种组分存在相互表面单层分散,即在一定的相对含量范围内,该体系的任一组分的微晶固溶体都既接受另一组分在其表面上的单层分散,同时也在另一组分的微晶固溶体表面上单层分散.相互单层分散和固溶体的生成都可能使高温焙烧时微晶的增大受到抑制,从而维持了样品的高比表面. 展开更多
关键词 共沉淀法 物相表征 zro2 al2o3 纳米复合氧化物 相互单层分散 陶瓷 二氧化锆 三氧化二铝
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Al_2O_3/ZrO_2(Y_2O_3)复合材料断裂过程中的相变及力学性能 被引量:8
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作者 马伟民 修稚萌 +2 位作者 毕孝国 闻雷 孙旭东 《金属学报》 SCIE EI CAS CSCD 北大核心 2005年第1期93-98,共6页
用真空烧结方法制备了Al2O3/ZrO2(Y2O3)复合材料,分析了ZrO2(3Y)和ZrO2(2Y)含量对Al2O3基陶瓷抗弯强度、断裂韧性的影响.用XRD定量分析了含摩尔分数2%与3%Y2O3的ZrO2(2Y)与ZrO2(BY)在断裂过程中四方相转变成单斜相的相变量,用以阐明... 用真空烧结方法制备了Al2O3/ZrO2(Y2O3)复合材料,分析了ZrO2(3Y)和ZrO2(2Y)含量对Al2O3基陶瓷抗弯强度、断裂韧性的影响.用XRD定量分析了含摩尔分数2%与3%Y2O3的ZrO2(2Y)与ZrO2(BY)在断裂过程中四方相转变成单斜相的相变量,用以阐明增韧机制.结果表明,在ZrO2含量为15%(体积分数)时,Al2O3/ZrO2(3Y)和Al2O3/ZrO2(2Y)复合材料的抗弯强度、断裂韧性分别达到825 MPa,7.8 MPa·m1/2。和738 MPa,6.7 MPa·m1/2,两者的性能差异主要来自不同的增韧机制. 展开更多
关键词 al2o3/zro2复合材料 真空烧结 相变增韧 力学性能
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纳米ZrO_2对Al_2O_3陶瓷性能的影响 被引量:12
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作者 高翔 丘泰 +1 位作者 焦宝祥 沈春英 《硅酸盐通报》 CAS CSCD 北大核心 2005年第1期12-16,共5页
以纳米ZrO2,微米A l2O3为原料,采用无压烧结方式制备了ZTA复相陶瓷。结果表明:纳米ZrO2的加入有利于制备细晶ZTA复相陶瓷。此外,nano-ZrO2的加入对A l2O3陶瓷的显微结构也产生影响,ZrO2颗粒以“晶内型”和晶界型2种形式存在。合理的配... 以纳米ZrO2,微米A l2O3为原料,采用无压烧结方式制备了ZTA复相陶瓷。结果表明:纳米ZrO2的加入有利于制备细晶ZTA复相陶瓷。此外,nano-ZrO2的加入对A l2O3陶瓷的显微结构也产生影响,ZrO2颗粒以“晶内型”和晶界型2种形式存在。合理的配方组成及制备工艺有利于ZrO2以四方亚稳相存在。ZrO2质量分数为30%时,其四方相质量分数可达69%,有利于应力诱导相变增韧,该ZTA复相陶瓷的抗弯强度、断裂韧性分别达到604M Pa,6.87M Pa·m1/2。 展开更多
关键词 纳米zro2 复相陶瓷 ZTA al2o3陶瓷 无压烧结 质量分数 制备 MP 影响 诱导
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Al含量对Pt-SO_4^(2-)/ZrO_2-Al_2O_3固体超强酸催化正戊烷异构化性能的影响 被引量:13
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作者 宋华 董鹏飞 张旭 《物理化学学报》 SCIE CAS CSCD 北大核心 2010年第8期2229-2234,共6页
通过向SO24-/ZrO2催化剂中同时引入适量的Pt和Al2O3,制备出了具有较高催化性能和稳定性的Pt-SO24-/ZrO2-Al2O3型固体超强酸催化剂.以正戊烷异构化反应为探针,考察了Al含量对催化剂性能的影响;并采用X射线衍射(XRD)、比表面积测定(BET)... 通过向SO24-/ZrO2催化剂中同时引入适量的Pt和Al2O3,制备出了具有较高催化性能和稳定性的Pt-SO24-/ZrO2-Al2O3型固体超强酸催化剂.以正戊烷异构化反应为探针,考察了Al含量对催化剂性能的影响;并采用X射线衍射(XRD)、比表面积测定(BET)、红外(IR)光谱、程序升温还原(TPR)、热重-差热分析(TG-DTA)和氨-程序升温脱附(NH3-TPD)手段对催化剂进行了表征.结果表明,Al能够提高ZrO2的晶化温度,抑制硫的分解,增加催化剂的比表面积,增强硫氧键的结合,提高催化剂的还原性能,增加催化剂的酸强度和酸总量.当Al2O3含量(质量分数,w)为5.0%时,Pt-SO24-/ZrO2-Al2O3固体超强酸催化剂的催化活性最好,在100h内异戊烷收率可稳定在52.0%以上,选择性在98.2%以上. 展开更多
关键词 固体超强酸 催化剂 So24-/zro2 异构化 al2o3含量 PT
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纳米Al_2O_3/ZrO_2复合粉体的制备及表征 被引量:11
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作者 陈国清 张凯锋 +1 位作者 王国峰 张蕾 《材料科学与工艺》 EI CAS CSCD 2004年第1期20-23,28,共5页
高性能的复合粉体是制备纳米复相陶瓷材料的关键.采用醇-水溶液加热法结合共沉淀过程制备纳米Al2O3/ZrO2复合粉体,研究了不同沉淀剂对粉体团聚的影响,利用透射电镜、X射线衍射、热重-差热分析、比表面积测定等技术对获得的纳米复合粉体... 高性能的复合粉体是制备纳米复相陶瓷材料的关键.采用醇-水溶液加热法结合共沉淀过程制备纳米Al2O3/ZrO2复合粉体,研究了不同沉淀剂对粉体团聚的影响,利用透射电镜、X射线衍射、热重-差热分析、比表面积测定等技术对获得的纳米复合粉体进行了表征.结果表明:采用NH4HCO3作为沉淀剂可以得到几乎无团聚的碱式碳酸盐前驱物,该前驱物在煅烧过程中的物相变化显示四方相氧化锆(t ZrO2)的形成温度大幅度地提高,同时在较低温度下生成了α Al2O3,在1100℃转变为t ZrO2相和α Al2O3相;粉体中两相颗粒分散良好、粒径一致、无硬团聚,其平均粒径为15~20nm,比表面积为69 5m2·g-1. 展开更多
关键词 纳米al2o3/zro2复合粉体 制备工艺 沉淀剂 氧化锆 氧化铝 陶瓷材料
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Microstructure and microwave dielectric properties of lead borosilicate glass ceramics with Al_2O_3 被引量:4
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作者 韦鹏飞 周洪庆 +2 位作者 王杰 张一源 曾凤 《Journal of Central South University》 SCIE EI CAS 2011年第6期1838-1843,共6页
The effects of Al2O3 addition on both the sintering behavior and microwave dielectric properties of PbO-B203-SiO2 glass ceramics were investigated by Fourier transform infrared spectroscope (FTIR), differential ther... The effects of Al2O3 addition on both the sintering behavior and microwave dielectric properties of PbO-B203-SiO2 glass ceramics were investigated by Fourier transform infrared spectroscope (FTIR), differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that with the increase of Al2O3 content the bands assigned to [SiO4] nearly disappear. Aluminum replaces silicon in the glass network, which is helpful for the formation of boron-oxygen rings. The increase of the transition temperature Tg and softening temperature Tf of PbO-B2O3-SiO2 glass ceramics leads to the increase of liquid phase precipitation temperature and promotes the structure stability in the glasses, and consequently contributes to the decreasing trend of crystallization. Densification and dielectric constants increase with the increase of Al2O3 content, but the dielectric loss is worsened. By contrast, the 3% (mass fraction) Al2O3-doped glass ceramics sintered at 725℃ have better properties of density p=2.72 g/cm3, dielectric constant Er=6.78, dielectric loss tan8=2.6×10^-3 (measured at 9.8 GHz), which suggest that the glass ceramics can be applied in multilayer microwave devices requiring low sintering temperatures. 展开更多
关键词 Pbo-B203-Sio2 glass ceramics al2o3 Fourier transform infrared spectroscope MICRoSTRUCTURE dielectric properties
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