摘要
以硝酸铝和正硅酸乙酯为主要原料制备稳定莫来石溶胶,用浸渍包膜的工艺方法对钛酸铝(Al2TiO5,AT)粉体进行包裹,研究了溶胶性能及含量对钛酸铝粉体包裹效果及性能改善的影响。结果表明:溶胶的浓度为0.18-0.30 mol/L、黏度在56-93 mPa.s之间、pH=3.0、包膜厚为0.15-0.20μm时,可得到包裹效果良好的莫来石钛酸铝粉体,制备出性能优良的莫来石-钛酸铝复合材料。复合材料的抗折强度为36-50 MPa,为钛酸铝材料强度的10-15倍,复合材料的热膨胀系数为1.89-2.25×10-6/℃(室温至1000℃),复合材料中的钛酸铝在1100℃/300 h的热处理未发生分解。应用TG-DSC、XRD、SEM、EPMA等对包膜前后莫来石粉体和复合材料粉体的热学行为、形貌和成分进行研究,探讨了性能与结构之间的关系。
The stable mullite sol with different performances was prepared by the sol-gel method using tetraethyoxysilane（TEOS） and aluminium nitrate as main materials. Aluminium titanate（AT） powders were covered by mullite sol using the dipping film-coating method. The influences of performance and relative amount of mullite sol on the coating effect and improvement of performance of AT powders were researched. The results show that when the concentration of mullite sol is in the range of 0. 18-0. 30 mol/L, viscosity of mullite sol 56-93 mPaos, pH value 3. 0, and coating thickness 0. 15-0.20 μm, the mullite- aluminum titanate powder with better coating and mullite-aluminum titanate composite material with good performance can be obtained. The bending strength of mullite aluminum titanate composite material reaches 38-50 MPa, which is 10-15 times that of aluminum titanate material, and the thermal expansion coefficient is 1.89-2.25 × 10^-6/℃ （room temperature to 1000℃）. The aluminium titanate powders covered with mullite film do not decompose at 1100 ℃ for 300 h. The heated process and the feature of aluminium titanate before or after coating the film, and its compositions were investigated by TG-DSC, XRD, SEM, EPMA, etc. The relationships between performances and structure of the powders and the composite material of mullite-aluminum titanate were studied.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2007年第1期97-103,共7页
Acta Materiae Compositae Sinica
基金
教育部科学技术研究重点项目(02078)
关键词
莫来石溶胶
钛酸铝
浸渍包膜
性能改善
mullite sol
aluminium titanate
dip film-coating
improvement of performance
