用Sol-Gel法制备喷墨打印用BaTiO3陶瓷墨水

用Sol-Gel法，通过控制异丙醇肽和醋酸钡的水解速率制备了BaTiO3陶瓷墨水，研究了陶瓷墨水的制备工艺参数，分散剂添加量，导电盐添加量，pH值，固相含量等对墨水性能的影响，用扫描电镜观察了BaTiO3B 墨滴打印点和单一打印层的形貌，发现陶瓷墨滴大小均匀，打印层表面平整。该墨水满足连续式喷墨打印要求。     

用乳化分散法制备喷墨打印用Al_2O_3陶瓷墨水

以纳米α-Al_2O_3为原料,用乳化分散法制备出了分散性、稳定性良好的 Al_2O_3陶瓷墨水,研究了墨水的理化性能。结果表明,Al_2O_3墨水稳定性随分散剂 EFKA-4300加入量增加而增大,在2.5Vol%Al_2O_3墨水中,EFKA-4300的最佳加入量为6wt%;墨水的粘度随Al_2O_3体积份的增加而增大。打印实验证明乳化分散法制备的 Al_2O_3陶瓷墨水能够满足喷墨打印的要求。     

BaTiO3-Nb2O5-Ni2O3三元系统的介电性能研究

对三元系统BaTiO3-Nb2O5-Ni2O3的微结构和介电性能进行了研究．XRD分析表明Nb2O5／Ni2O3协同掺杂的BaTiO3陶瓷为赝立方相结构；在掺杂1．0mol％Ni的BaTiO3中，Nb的固溶度〈4．0mol％．SEM观察表明，随Nb掺杂量的增加，BaTiO3陶瓷的晶粒尺寸先增大后减小．BaTiO3陶瓷的室温介电常数、介质损耗，以及在低温端和高温端的电容变化率都随Nb含量的增加而先增大后减小．DSC测量表明，Nb掺杂使BaTiO3陶瓷的居里温度向高温方向移动．该系统瓷料介电性质的变化与材料的晶粒尺寸以及掺杂剂导致的相变温度的移动密切相关．本实验在BaTiO3-Nb2O5-Ni2O3系统中开发出了新型的X8R材料，这种材料很有希望用于制备大容量X8R多层陶瓷电容器．     

BYPT-BT高居里温度压电陶瓷的相结构与电性能

采用固相合成法制备了BiYbO3-PbTiO3-BaTiO3(BYPT-BT)压电陶瓷材料.通过差热分析(DSC)和热失重分析(TG)确定了BYPT-BT陶瓷钙钛矿相的形成温度,研究了不同含量的BaTiO3对BYPT-BT陶瓷相结构及电性能的影响规律.结果表明,BYPT-BT陶瓷由钙钛矿相和焦绿石相Yb2Ti2O7组成,随着BaTiO3含量的增加,焦绿石相Yb2Ti2O7逐渐减少.居里温度丁T和介电损耗tanδ随着BaTiO3含量的增加逐渐减少,介电常数ε,则随之而增大.     

钛酸铋钠掺杂对BaTiO3-Nb2O5-ZnO系统介电性能的影响

研究了Bi0.5Na0.5TiO3(BNT)掺杂对BaTiO3(BT)-Nb2O5-ZnO三元系统介电性能与微结构的影响.BaTiO3陶瓷在低温端(-55℃)的电容量变化率随BNT含量的增大而单调降低,而高温端(150℃)的变化率持续增大,且居里温度单调递增.掺杂1.0wt%与2.5wt%BNT的BT陶瓷满足EIA XSR特性.SEM观察表明,BaTiO3陶瓷内部由细小的基质晶粒和第二相晶粒组成,且第二相比例随BNT含量的增加而增大.XRD分析表明,基质晶粒为BaTiO3,第二相晶粒为CaB2Si2O8和NaBiTi6O14.条状第二相CaB2Si2O8和NaBiTi6O14的产生改变了BT系统的内应力结构是钛酸钡陶瓷居里温度升高以及电容量温度特性改善的原因.     

喷射打印用ZrO2陶瓷墨水的研究进展

以ＺｒＯ２超细粉为研究对象，使用海藻酸钠和聚丙烯酸作分散剂，制备出分散稳定性良好且可满足打印要求的不同固相含量的ＺｒＯ２陶瓷墨水，并对固相含量与墨水的各种理化性能之间的关系进行了探讨。     

用反相微乳液法制备陶瓷墨水

在水/Span80-Tween60/环已烷反相微乳液体系中制备出适合喷射打印成型用分散性好、微粒尺寸约10nm的ZrO2陶瓷墨水,研究了陶瓷墨水的理化性能,当复合乳化剂含量为0.15～0.20,HLB值11.5～13.5,水含量16.0时,得到了澄清、稳定的反相微乳液。陶瓷墨水的粘度随固含量的增加而增大,加入助乳化剂可以调节粘度和表面张力,加入少量助乳化剂也可以提高体系含水量。     

水基流延制备BaTiO3基PTC片的研究

通过水基流延制备BaTiO3基PTC片,陶瓷粉体采用固相合成预烧BaTiO3基PTC粉体,平均粒径为1.0μm,粘合剂采用浓度为12%的PVA溶液和B-1070乳液,分散剂采用D-3019(Rohm-Hass),增塑剂分别采用化学纯的丙三醇、邻苯二甲酸二丁脂和聚乙二醇PEG400,消泡剂采用化学纯的正辛醇,溶剂为水.主要讨论了分散剂的用量和粘度的关系、浆料的固相含量和粘度的关系、不同粘合剂浆料的流变行为、不同粘合剂的热失重特性等,发现采用PAA乳液粘合剂无论是在固含量、粘度以及烧成后电性能都优于PVA粘合剂,因此更适合于BaTiO3水基流延,当分散剂用量为粉体0.50%(质量分数)时,浆可以获得固相含量高达86.0%左右粘度仅为490mPa·s的BaTiO3陶瓷浆料.     

α-Al2O3/ZrO2(3Y)复相陶瓷悬浮体的流变性能

研究了分散剂添加量、固相体积分数、研磨时间及复合粉体组成对á-Al2O3/ZrO2(3Y)复相陶瓷悬浮体流变性能的影响.结果表明:当pH值在9.0左右,分散剂添加量为1.20wt%时,á-Al2O3/ZrO2(3Y)(30wt%ZrO2)悬浮体的粘度和剪切应力值较低,悬浮体的粘度和剪切应力值随固相体积分数和ZrO2含量增加而增加,当ZrO2含量较高时,适当调整分散剂添加量,仍可制备流变性较好的悬浮体.在本实验条件下,研磨4h的悬浮体的流变性最佳.     

Al_2O_3陶瓷膏体3D打印挤出成型流变性（英文）

陶瓷膏体3D打印挤出成型工艺中,膏体具有低粘度,高稠度和流变性是陶瓷膏体配制需要保证的关键性能,对坯体的密度、成形精度等有较大影响,进一步影响陶瓷器件的成品率。陶瓷膏体的流变性受较多因素影响,本研究通过单因素实验和正交实验研究了固相含量、分散剂含量、pH值和球磨时间对陶瓷膏体流变性能的影响,获得了适应于3D打印挤出成型工艺流变性的A12O3陶瓷膏体,并利用得出的膏体进行打印成型实验和性能分析。研究结果表明:随着固含量的增加,膏体的粘度逐渐增加,流变性能下降。相反,随着分散剂含量和球磨时间的增加,膏体的粘度先减小后增加,而流变性能先增加后减小。另外,随着膏体pH值的升高,粘度先增大后减小,而流变性能先减小后逐渐增大。当固相含量、分散剂含量、pH值和球磨时间分别为51vol.%、0.3vol.%、3和36h时,可以获得具有较好流变性能的陶瓷膏体。     

纳米钛酸钡掺杂聚酰亚胺基高介电复合薄膜的制备及性能

采用原位聚合法和高速砂磨法制备了纳米钛酸钡/聚酰亚胺高介电常数复合薄膜,分析了不同制备方法及钛酸钡粉体用量对复合薄膜结构和性能的影响。实验结果表明,高速砂磨法对于纳米钛酸钡粉体的分散效果优于原位分散法;钛酸钡粉体的引入,有效提高了复合薄膜的热稳定性和介电性能。当粉体的体积分数达到50%时,复合薄膜介电常数相较于纯膜提高了10倍,而介电损耗只有少量增加。     

The influence of poly(acrylic acid) molar mass and concentration on the properties of polyalkenoate cements Part II Young''s modulus and flexural strength

The Young's modulus and flexural strength were determined for glass polyalkenoate cements as a function of poly(acrylic acid), PAA molar mass, concentration, glass volume fraction and cement ageing time. The Young's modulus was independent of PAA molar mass. The Young's modulus increased dramatically with the PAA concentration of the cement until concentrations greater than 50% m/m were reached. The modulus increased with time for nearly all the cements investigated consistent with a continuing ionic cross-linking process in the cement matrix. The modulus increased with an increase in the volume fraction of the higher modulus glass phase. Increasing the glass volume fraction provides more surface area for acid attack resulting in a more cross-linked polysalt matrix, as well as increasing the volume fraction of residual glass particles. Flexural strength was highly dependent on molar mass of the PAA and its concentration. The molar mass dependence of the flexural strength was greatest at higher PAA concentrations.     

The influence of poly(acrylic acid) molar mass and concentration on the properties of polyalkenoate cements Part I Compressive strength

The influence of poly(acrylic acid), PAA molar mass, concentration and glass volume fraction were investigated on the compressive strength of polyalkenoate cements after ageing for 1, 7 and 28 days in water at 37°C. The compressive strength increased with the molar mass of the polyacid. The increase in compressive strength with molar mass was greater at higher PAA concentrations. Increasing the polyacid concentration generally increased the compressive strength, until PAA concentrations greater than 50% m/m were achieved. Increasing the glass volume fraction had little influence on the compressive strength of cements made with low PAA concentrations, however the compressive strength increased with glass volume fraction for cements that had a high PAA concentration. Increasing the ageing time of the cement prior to testing generally resulted in an increase in compressive strength. However the influence of ageing time was greater in cements made with high PAA concentrations.     

提高AEO9/醇/烷/水体系反相微乳液陶瓷墨水浓度的研究

鉴于陶瓷墨水在某些性能上存在不足,例如相对连续式喷墨打印机打印成型要求而言粘度较大、电导率偏低、固相含量不够高等问题,通过加入醇和Na₂CO₃等添加剂以及利用双连续结构分别对粘度、电导率等性能加以调整及提高陶瓷墨水的浓度。少量醇的加入(1％～2％)使陶瓷墨水体系粘度降低到11mPa·S左右,根据相图从双连续结构角度出发设计了陶瓷墨水的组成,考察了溶水量的变化,并借以提高陶瓷墨水固相含量,使其达到2.54％。由于双连续结构陶瓷墨水的理化性能(粘度、电导率等)仍不能完全满足要求,加入少量Na₂CO₃进行改性,改性后的陶瓷墨水粘度降至18mPa·s以下,电导率接近100mS/m,稳定性良好,墨水中陶瓷颗粒粒度在10nm以下,但透光率略有降低,显微结构观察表明具有明显的双连续结构特征。     

BaTiO_3粉体的预处理及其对陶瓷烧结与介电性能的影响

以工业生产的BaTiO3粉体为基础原料,探讨不同预处理条件及Sr、Y元素掺量对BaTiO3陶瓷显微结构及介电性能的影响。结果表明:掺杂少量的Sr、Y元素可促进BaTiO3晶体向四方相转变;用乙醇作球磨介质处理粉体并在900℃预烧,可促进陶瓷的致密烧结和晶粒细化;掺杂摩尔分数为1.0%的Sr,可使居里温度降低2℃,室温相对介电常数提高到2 400以上;掺杂Y元素可使陶瓷的居里温度升高,并显著提高陶瓷的介电常数,Y元素掺量为0.3%(摩尔分数)时,室温相对介电常数达到21 000以上。     

Highly loaded alumina inks for use in a piezoelectric print head

Ink jet printing techniques are used for an increasing number of materials and applications. Properties of the used inks have great influence on process stability and accuracy as well as the resulting part properties. Inks containing ceramic particles have been applied in various studies and applications. The criteria identifying suitable inks vary depending on the applied printing technology. In this study, inks for application in a piezoelectric print head were investigated. Alumina inks with solid loadings up to 21 vol.‐% were prepared and characterized. The Influence of different solid loadings, dispersant concentrations and binding agents was examined. The prepared inks show sufficient stability and fit literature recommendations for successful drop ejection. Considering rheological aspects, two inks with light shear‐thinning behaviour and viscosities of 18 mPas and 23 mPas at high shear rates were recommended for upcoming printing tests. The Re/We^1/2 ratio can be used for predetermination of print ability but the influence of the surface tension is not sufficiently taken into account using the presented calculations. So further printing experiments are essential for clarification of the calculations and obtained print ability values.     

氧化铝陶瓷凝胶注模成型工艺的研究

探讨了陶瓷凝胶注模成型的机理和特点,研究了固相体积含量、pH值、分散剂等对制备低粘度、高固相体积含量的氧化铝陶瓷悬浮液的影响.实验结果表明,固相体积分数为55%,浆料的粘度可以满足注模的需要时坯体抗弯强度可达30MPa.控制pH值为9左右,加入8%(质量分数)的PMAA-NH4分散剂,可制得粘度低、流动性好适宜于复杂形状制品注模的陶瓷浆料.     

Preparation, Characterization, and Gelation of Temperature-Induced Forming (TIF) Alumina Slurries

Temperature-induced forming is a novel direct-casting method that has potential for ceramic industry applications. Less than 0.5 wt.% TAC and PAA were used to prepare TIF alumina slurries. These slurries were gelled to form alumina parts by controlling temperature only. The viscosity of the PAA addition slurries increases with temperature, while the viscosity of PAA-free slurry has no evident change in the experimental temperature range. The temperature dependence of modulus showed that the slurries had "fluidlike" to "solidlike" transition that lead to gelation of TIF slurries. The composition-gelation diagram under the experimental conditions is also reported. By tailoring the slurry solid loading and PAA concentration, complex shape alumina ceramic parts with good surface finish and green density of about 65% theoretical density were successfully fabricated by TIF direct casting.     

Dispersion and stability of silver inks

Different dispersants were used to develop ethanol-based silver inks for continuous ink-jet printing. Inks were made using varying amounts of dispersant and silver. Various parameters, such as sedimentation behaviour, sediment volume, half-value time and viscosity, were used to assess the dispersion and stability of these inks over 10 days.     

分散剂在BaTiO3浆料中的分散机理

分散剂能降低分散体系中物质的聚集。在制备BaTiO3陶瓷浆料时加入分散剂,有利于形成分散液和悬浮液。本文分析了分散剂对浆料颗粒形状的影响机理,它是使颗粒间形成双电层的厚度增加,导致了颗粒间静电斥力变大,浆料悬浮并相对稳定。