摘要
研究了使用α-氧化铝微粉作为起始原料,以聚丙烯酸铵(PAA-NH4)为分散剂调配注浆成型用的浆料,采用注浆成型法制备出几乎没有缺陷的生坯,烧制出抗弯强度大于750 MPa的陶瓷体。探讨了分散剂添加量对浆料黏度的影响、浆料特性对生坯特性的影响以及烧结后样品的机械性能。注浆成型用浆料的特性是获得高强度氧化铝陶瓷的关键。经生坯特性(密度与微结构)观察、陶瓷体强度测试及破裂源检测提出一种浆料设计观点,即较佳的高分子分散剂添加量是达到饱和吸附以上但还未开始大量产生分子间架桥作用的浓度范围,此状态的浆料有助于增加粉体粒子之间的黏结,因而有效减少了生坯干燥过程中产生裂缝、缺陷的机率,促使陶瓷体强度得到明显提升。
Slurry used in slip casting is prepared using α-A l2 O3 powder as starting material and PAA-NH4 as dispersant.The green bodies with few defects were prepared by slip casting method and the ceramics with bending strength being above 750 MPa were sintered.The effect of dispersant addition on slurry viscosity,and the effect of slurry properties on green body and the mechanical performance of sintered body were investigated, respectively.The properties of slurry used in slip casting were critical to obtain the high-strength Al2O3 ceramics.A view for designing slurry was proposed by observing the density and mi-crostructure of green body,the strength of sintered body and detecting the rupture source was measured,that was the addition of PAA-NH4 can be controlled in a concentration range which corresponding to higher than the level of saturated adsorption but lower than the level that caused the bridging effect between polymer molecules.The non-adsorption polymer could be re-garded as the binder that provided the sufficient binging force between alumina particles and thus reduced the formation of flaws in the green bodies during the drying process.And then the strength of Al2O3 ceramics could be significantly enhanced.
出处
《无机盐工业》
CAS
北大核心
2017年第9期17-22,共6页
Inorganic Chemicals Industry
基金
国家自然科学基金项目(51404056)
中央高校基本科研业务费资助(N130402015)
