氮化铝陶瓷浆料流变性能的研究

系统地研究了流延法制备氮化铝基片过程中影响流延浆料粘度的主要因素.分析了研磨时间、有机混合溶剂掺量、分散剂掺量及粘结剂、塑性剂对氮化铝浆料流变性能的影响,并对实验条件下测得的流变曲线采用Hershel Bulkley模型进行拟合,拟合出的Hershel Bulkley屈服应力τc较好地反映了浆料的稳定性,研究结果表明:分散剂掺量为2.5%(体积分数)时,浆料的τc较低;浆料的τc随固相体积分数的增加而增加;研磨时间为4h制备的浆料τc最低,流动性能最好;浆料的粘度随着塑性剂与粘结剂的比值R的增加而急剧减小,流变性能得到明显改善.     

氮化铝基板流延成型浆料的研究

系统地研究了流延法制备氮化铝基片过程中有机添加剂对氮化铝浆料流变性能的影响,采用NDJ-11旋转式粘度计测定浆料的流变性能,结果表明:混合溶剂二甲苯/异丙醇对粉料的湿润性能最好,粉体的悬浮性能和浆料流变性能最佳;浆料的粘度随着塑性剂与粘结剂的比值R的增加而急剧降小,流变性能得到明显改善.     

Ba2Ti9O20陶瓷流延浆料的流变性能和流延成型研究

以BaCO3和TiO2粉末为原料,采用固相反应法合成Ba2Ti9O20的粉体,并以此粉体为主要原料添加适量的分散剂、粘结剂及塑性剂,采用流延法制备Ba2Ti9O20陶瓷膜片。研究了不同种类和配比的溶剂、不同种类和含量的分散剂对Ba2Ti9O20流延浆料的流变特性的影响。结果表明,当选用异丙醇和甲苯(体积比为75:25)为溶剂,固含量Ba2Ti9O2054wt%,分散剂蓖麻油0.5wt%,粘结剂聚乙烯醇缩丁醛5wt%,塑性剂聚乙二醇5wt%时,流延浆料的流变性能较好,浆料的粘度为9.1Pa.s。     

添加剂对Li1.075Nb0.625Ti0.45O3微波介质陶瓷水基流延浆料的影响

以聚乙烯醇为粘结剂,乙二醇为增塑荆,聚羧酸铵盐为分散剂,对Li1.075Nb0.625 Ti0.4sO3微波介质陶瓷的水基流延成型工艺进行了研究.在以水为溶剂的条件下,考察了分散剂、粘结剂、增塑剂对浆料粘度和稳定性的影响以及流延浆料的流变特性.结果表明,分散剂对浆料粘度的影响较大,其最佳用量为粉体的0.2%(质量分数).聚乙烯醇水溶液能增加浆料的粘度,并提高浆料的稳定性;乙二醇虽然能降低浆料的粘度,但对其稳定性的影响不大.Li1.075Nb0.625 Ti0.45O3水基流延浆料为典型的假塑性流体,并且不存在触变性;SEM观察表明,流延成型后陶瓷素坯膜的微观结构均匀.     

含镁离子电解质对氧化铝浆料流变性能的影响

通过高纯氧化铝陶瓷浆料粘度和zeta(ζ)电位等参数的考察,探讨了不同pH值下,含镁离子电解质对其流变性能的影响。结果表明,镁离子会降低氧化铝浆料的流变性能。在其存在下,无分散剂时与添加聚丙烯酸(PAA)作分散剂时,pH值分别为6.5和9.5的浆料具有良好的流变性能。无镁离子存在时,PAA的最佳添加量为0.5%;镁离子浓度为0.05mol/L时,该量增加至0.9%。     

添加BCB助烧剂的CLST陶瓷流延浆料流变性能研究

研究了有机物对CLST陶瓷流延浆料性能的影响.结果表明:体积比为1∶3的乙醇与氮-氮二甲基甲酰胺为混合溶剂对粉料的湿润性能最好,以聚乙烯醇缩丁醛( PVB)为粘结剂,邻苯二甲酸二丁酯为增塑剂,蓖麻油为分散剂配制了CLST陶瓷流延浆料.当w(分散剂)为0.8％,w(粘结剂)为8％,固相体积分数为50％,R(增塑剂:粘结剂...     

水基流延浆料性能影响因素分析

水基流延法是在传统流延法上进行改进,采用水作溶剂制备片层陶瓷基板的一种方法。分子间作用力、静电力和空间位阻的共同作用,构成水基流延浆料的稳定机理;粉体的颗粒尺寸和粒径分布对流延生坯的性能具有重要影响;选择合适的添加剂种类和加入量能极大地改善水基流延浆料的流变性和稳定性,同时可提高流延生坯的可加工性;球磨工艺和真空除泡工艺的选择对于制得良好的水基流延浆料也很重要。     

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.     

熔融碳酸盐燃料电池电极用镍粉浆料的流变学研究

流延成型法是目前制备熔融碳酸盐燃料电池电极板的主要工艺。本文以环己酮 丁醇为溶剂 ,三油酸甘油酯为分散剂 ,以聚乙烯醇缩丁醛为粘结剂 ,聚乙烯乙二醇为增塑剂 ,通过球磨工艺制备了非水基羰基镍粉浆料。详细研究了分散剂用量 ,粘结剂 分散剂用量及其比例对镍粉浆料流变学性能的影响 ,并将浆料流延成型 ,研究了素坯的密度、力学性能和微观结构与浆料流变学行为的相关性     

PAANH4-凹凸棒石粘土水悬浮液分散稳定性研究

研究了PAANH4 凹凸棒石粘土水悬浮液分散稳定性。结果表明 :固相质量分数不同的浆料 ,其最佳分散剂添加量均为 4 .5 %。固相质量分数的提高 ,浆料最低粘度值提高 ,分散剂有效用量范围变窄。对于给定PAANH4 添加量的浆料 ,其流变性随着pH的提高有明显的改善 ;pH值为 6 .5的悬浮液 ,经过高于 6 .5阶段的吸附 ,其流变性能均显著改善 ,而经过pH值为 8.5阶段的吸附的悬浮液粘度值最小。     

煤系高岭土光固化浆料的流变性能EI北大核心CSCD

基于光敏树脂体系制备煤系高岭土光固化浆料,采用流变仪对浆料的流变性能进行表征,研究分散剂和增塑剂加入量对浆料流变性能的影响。结果表明:油酸作为分散剂具有降低浆料黏度的效果,当油酸加入量为高岭土粉体的1%(质量分数)时浆料的黏度最小,在该条件下40%(体积分数)高岭土浆料的黏度为49.56 Pa·s。加入增塑剂PEG-300能够进一步降低浆料的黏度,浆料黏度随着增塑剂加入量的增加而减小,当增塑剂加入量为光敏树脂的20%(质量分数)时40%(体积分数)高岭土浆料的黏度下降为19.77 Pa·s,已经能较好地满足浆料涂布的要求。采用流变性能优化的浆料进行光固化成形,经过排胶、烧结后得到复杂形状的高岭土陶瓷件。     

Dispersion and tape casting of silicon carbide through aqueous route

Dispersion behaviour of SiC in aqueous media was studied using four different dispersants and as a function of pH. The slurry was characterized in each case by sedimentation, viscosity and rheological studies. The best dispersant was selected and its optimum amount was determined. For this system, the pH was varied over a range of 2–11. The slurry displayed the minimum viscosity as well as near-Newtonian behavior at pH range 8–11. SiC tapes were obtained by Double doctor blade tape-casting process, with polyvinyl alcohol as binder and PEG and BBP as plastisizers. The stability of the tape casting slurry was determined by rheological characteristics. As-cast tapes were dried in air at room temperature. The results show that it is possible to obtain homogenous defect-free green tapes of 57.7% solid loading and 53% green density with smooth surface using the optimized tape casting slurry.     

Dispersion and rheological studies of Y-PSZ tape casting slurry

Different solvent systems in combination with three different dispersants were tried to find out the suitable solvent-dispersant combination, which give optimum dispersion of PSZ. Based on sedimentation, viscosity and rheology characteristics, zeotropic ethanol : xylene with a ratio of 50 : 50 along with 0.5 wt% phosphate ester was found to be the best solvent and dispersant combination. Optimized tape casting slurry was prepared using PEG 600 and BBP as plasticizers and PVB as the binder. Cyclohexanone was used as the homogenizer. The optimized slurry composition with 58% solid loading exhibited shear-thinning pseudoplastic rheological behaviour. Y-PSZ tapes of ∼ 50 Μm thickness free from visible defects were cast with a green tape density of 55%.     

Tape casting of AlN/glass composites for LTCC substrate

AlN/glass composite is low-fired substrate material for microelectronic packaging material. In this work, AlN/glass sheets were prepared by tape casting process. The dispersion, stabilization and the rheological properties of the slurry were studied. The optimum drying condition and mechanisms of debinding were also investigated. The results showed that powder size influenced the optimum content of dispersant and the viscosity of slurry. The slurry for tape casting exhibited a typical shear-thinning behavior. Smooth green tape without cracking was acquired after it was dried at solvent atmosphere. The binder was fully burned out at 600°C at low heating speed. The lamination with uniform microstructure was achieved by hot-pressed at 900°C.     

改性甲基丙烯酸共聚物分散剂对陶瓷复合料浆流变性及坯体强度的影响

烯丙基聚氧乙烯醚与甲基丙烯酸和甲基丙烯酸甲酯可通过自由基共聚获得两亲结构的水溶性高分子MPMA , 可作为陶瓷浆料分散剂。研究了MPMA 用量对石英/ 长石/ 粘土复合浆料流变性及坯体强度的影响, 并分析了其原因及分散稳定作用机理。结果表明: MPMA 的加入显著优化了料浆的流变性能并提高了成型后陶瓷的强度。在p H 值为9～10 时, MPMA 的最佳用量为0. 57 wt %(相对绝干浆料) , 料浆的Zeta 电位绝对值由28. 5 mV升高到65. 5 mV , 零剪切黏度由690. 9 mPa·s 降低到81. 6 mPa·s , 触变面积最小, 陶瓷料浆基本呈Newton流动特性, 显示了很好的分散性。与添加无机分散剂的陶瓷坯体相比, 添加MPMA 的陶瓷坯体强度由160 MPa升高到268 MPa 。      

Colloidal processing of lead lanthanum zirconate titanate ceramics

Well-dispersed aqueous slurries of fine ceramic powders with high solids loading are often required for various shape forming techniques such as slip and tape casting in order to fabricate advanced ceramics with a dense and uniform microstructure. Colloidal processing of lead lanthanum zirconate titanate (PLZT) powders was conducted at various pH using ammonium polymethacrylate as a dispersant. Suspensions were characterized by viscosity and zeta-potential measurements. The effect of pH on polymer adsorption and the rheological behavior of the slurries were investigated and stabilization mechanisms discussed. Through optimization of the dispersant concentration and pH, solids loadings of the suspensions up to 50 vol.% with a relatively low viscosity were obtained.     

氧化铝黑瓷浆料流变性能的研究

通过对氧化铝黑瓷粉料进行预烧技术处理,增大颗粒尺寸、降低粉体比表面能、改善其团聚现象,制备出固相体积分数达55%的氧化铝黑瓷稳定料浆,并研究了分散剂用量、体系固相体积分数、R值(塑性剂/粘结剂)对料浆流变性的影响.结果表明:浆料的粘度随剪切速率增加而下降,呈剪切稀化的流变学特性,随着固相体积分数的增加,浆料的最佳分散剂用量也相应增加;浆料的粘度随着R值的增加而急剧降低,流变性能得到明显改善.     

Influence of polyelectrolyte dispersant on slip preparation of nano-sized tetragonal polycrystals zirconia for aqueous-gel-tape-casting process

In this work, the conditions for the preparation of stable nanometer zirconia slurries with high solids content for the production of aqueous-gel-tape-casting objects with improved properties are identified. Influences of the powder and dispersant on the rheological properties were investigated. The result indicated the polyelectrolyte dispersant greatly affected the surface charge of nanometer tetragonal zirconia powder and the rheological behavior of nanoparticles zirconia’s suspensions. For each factor there exists an optimum range in which low viscosity was achieved for a slurry of high solid content. The proper content of the dispersant is between 0.8 and 1.2 wt.%. The rheology character of high solid loading slurries is non-Newtonian flow—‘shear-thinning’ character as the shear rate is increased. The viscosity of the 77 wt.% powder loading slurry with about 1.0 wt.% polyelectrolyte (based on the powder) was 0.35 Pa s at the shear rate of 110 s⁻¹. The slurry at the optimum conditions met the demands of aqueous-gel-tape-casting process.