SiC对反应烧结多孔Al_2TiO_5的物相及组织性能影响  

Effects of SiC on Phases,Microstructure and Mechanical Property of Porous Al_2TiO_5 Fabricated by Reaction Sintering

作　　者：崔洪芝[1] 李书海[1] 崔德运 

机构地区：[1]山东科技大学材料科学与工程学院,青岛266590

出　　处：《无机材料学报》2014年第5期509-514,共6页Journal of Inorganic Materials

基　　金：国家自然科学基金(51072104;51272141);山东省"泰山学者"计划(ts20110828)~~

摘　　要：本研究以γ-AlOOH、TiO2和SiC为原料,通过无压反应烧结制备了Al2TiO5多孔材料,分析比较了SiC粒度和含量对合成产物的物相组成、显微组织、抗压强度、孔隙率和孔径分布的影响。结果表明:反应产物的物相组成为Al2TiO5、Al6Si2O13、TiC、SiO2和Al2O3,还有少量未反应的TiO2。SiC与TiO2反应生成TiC和SiO2,TiC颗粒弥散分布于多孔材料壁面或者骨架中,而SiO2进一步与γ-AlOOH分解出的Al2O3反应生成Al6Si2O13晶须,晶须交错分布于Al2TiO5颗粒之间或者孔洞中,与TiC颗粒一起提高复合材料的抗压强度,特别是采用小粒径SiC时,对抗压强度的改善效果更加显著;添加大粒径SiC后,改变原有颗粒堆积状态,可提高复合材料的孔隙率。但当SiC含量超过5wt%时,因为生成较多低熔点的SiO2,部分填充于多孔材料的孔隙中,部分则分布于Al2TiO5晶粒之间,既减小孔隙率,又降低晶粒间结合强度和试样的抗压强度。Porous aluminium titanate （AT） composites were fabricated by sintering with γ-AlOOH, TiO2 and SiC as raw materials. Effects of the particle size and the content of SiC on phases, microstructures, compressive strength, porosity and pore size distribution of products were investigated. Results show that the phases of the products are composed of Al2TiO5（AT）, Al6Si2O13, TiC, SiO2, Al2O3 and a small amount of unreacted TiO2. When SiC is added into 7-AIOOH and TiO2 mixture, it reacts with TiO2 and forms TiC and SiO2. The small TiC particles distribute and disperse in the walls and shelves of porous products. Moreover, SiO2 reacts with Al2O3, decomposted from γ-AlOOH, to form Al6Si2O13 whiskers which distribute crisscross between Al2TiO5 grains or in the pores. The Al6Si2O13 whiskers along with TiC particles contribute greatly to improving the compressive strength of the products, particularly with small SiC particles. When SiC particles are big, the packing patterns of powder mixtures are changed and the porosities of the products are increased. However, when SiC content is beyond 5wt%, both the porosities and compressive strength of the products decrease due to the formation of more low-melting point SiO2, and some SiO2 fills in the pores of the porous products, and some exists on the surface of Al2TiO5 grains and weakens the bonding strength.

关 键 词：多孔材料 AL2TIO5 反应烧结 Al6Si2O13晶须 

分 类 号：TB332[一般工业技术—材料科学与工程]