【作者】 付长翼；

【导师】 罗凌虹；

【作者基本信息】 景德镇陶瓷学院 ， 材料学， 2009， 硕士

【摘要】 由于超细无机粉体颗粒的团聚严重及与极性高分子材料相容性较差等原因,给水系流延成型带来重重困难。本论文通过研究亚微米级氧化铝的表面改性,改善了以往工艺的分散效果,避免了亚微米级氧化铝颗粒间的团聚,提高其与高分子材料的相容性,并对其表面改性的规律及改性剂与颗粒间的作用方式进行了深入地探讨。本文利用溶胶—凝胶法在亚微米级氧化铝表面包裹氢氧化铝纳米涂层,使其能稳定地保持单个颗粒存在而不发生团聚,同时每个颗粒仍能保持很高的表面能与表面活性,使其在流延工艺中即可促进颗粒的分散稳定性,又能提高其烧结致密化。通过深入研究亚微米级氧化铝颗粒的特性、浆料pH值、粘结剂、分散剂、塑化剂的比例等因素对水基流延浆料流变学性能的影响,制备了分散稳定性良好,流动性适宜,适合流延成型的高固相体积分数的陶瓷浆料;结合流延工艺参数优化,得到了水基流延浆料的最佳配比范围。当pH值为9.0时,分散剂PAA含量为粉料的0.8wt%时,能获得稳定均匀分散、固含量为55vol%的氧化铝浆料。单纯PVA粘结剂制备的浆料粘度高、固含量低,流延片干燥速度慢,但强度高;单纯乳胶粘结剂制备的浆料粘度低、固含量高,流延片干燥速度快,但强度低。研究表明PVA与乳胶的化学相容性好,采用两种粘结剂复合,可以互补不足。当加入的粘结剂4.5wt%(乳胶:PVA=7:3),塑化剂PEG与PVA比例为1:1.3时,可制备出99氧化铝素坯片。本文系统研究了乳胶+PVA复合粘结剂体系的水基流延浆料的制备、流变学特性、浆料干燥及成膜机理,通过对浆料制备、流延过程及干燥控制等参数的优化,制备出表面光滑平整、结构均匀、强度和柔韧性较高、容易叠层和烧结的流延素片。该流延工艺制备的流延片,厚度可在50～1000um之间进行调控,素坯相对密度可以达到56%左右。制备的流延片在烧结温度1650℃、保温2小时的条件下获得了相对密度为98.5%、平整、半透明陶瓷基片。更多还原

【Abstract】 Due to the aggregation of inorganic particles and poor compatibility between the inorganic particles and polymer materials, it posed a great threat on aqueous tape casting. The surface modification of submicron Al₂O₃ was studied in the paper, which can avoid the aggregation and improve the compatibility with polymer materials; it was further discussed that the rules on modification of particle surface and the type of interaction between modified agents and particle.Al₂O₃ nano coat was wrapped on the surface of submicron Al₂O₃ by sol-gel, which can retain stably single particle without aggregation, meanwhile every particle still kept high surface energy and surface activity in order to exhibited excellent properties in tape casting technology. Namely, this promoted not only the dispersion stability of particle, but also the sintering densification. The influences of the characteristics of sub-micron Al₂O₃, pH of slurries, latex binder, dispersants and plasticzer on water-based tape casting process were studied systematically. Aqueous ceramic slurry with good stability, suitable fluidity and high powder loading was prepared successfully. The best range of slurry composition was got from the experiments. Aqueous ceramic slurry with good stability, suitable fluidity, and high powder loading was prepared successfully. The research showing: the chemical compatibility was good between PVA and latex. The better effect can be accessed using co-binder of PVA and latex. The stable slurry with solid loading of 55vol.% was produced under the pH value of 9.0 and dispersant PAA content of 0.8 wt%. The green tpae can be obtained via adding 4.5 wt% co-binder （latex : PVA =7:3）. The ratio of PEG and PVA was 1 : 1.3.In the paper, a co-binder, consisting of polyvinyl alcohol （PVA） and PAA latex, was used to prepare the 99 alumina substrate via aqueous tape casting. This paper focuses systematically on the relationship with the preparation of slurry, the forming of co-binder and the rheological behaviors of the suspensions. The aqueous tape casting process can produce green tapes with smooth surface, homogenous structure, high toughness and strength, easy lamination and sintering by improving technique parameters of tape casting process. The green tpae with 56% relative density and the thickness of 50-1000um can be obtained. The flat and translucent alumina substrate with above 98.5% relative density could be produced under the sintering temperature of 1650°C for 2 hours.更多还原