Effect of particle size on the lamellar pore microstructure of porous Al2O3ceramics fabricated by the unidirectional freezing
Porous Al2O3 ceramics with a lamellar pore microstructure have been fabricated by a directional freezing process using the micro-sized and nano-sized Al2O3 powders.At the same solid loading and freezing temperature,compared with the suspensions of micro-sized Al2O3,the porous ceramics prepared from the suspensions of nano-sized Al2O3 had the narrower lamellar pore channels and thicker channel walls,which were caused by the higher viscosity,stronger inter-particle attraction and more ice nucleation sites in the nano-sized Al2O3 suspensions.For both types of Al2O3at a specific solid loading,with the increasing of freezing temperature,the wider pore channels and thinner channel walls were observed.These tendencies were weaker by using the nano-sized Al2O3.The above results show the lower porosity in the ceramics using the nano-sized Al2O3.However,due to the higher sintering activity for the smaller particles,the pore channel walls by using the nano-sized Al2O3 was denser than using the micro-sized Al2O3,leading to the higher mechanical strength of ceramics.
Unidirectional freezing porous Al2O3 ceramic particle size lamellar pore microstructure
Xiao-yong Zhang Yan Zhang Dou Zhang
State Key laboratory for Powder Metallurgy, Central South University, Changsha 410083, China
国际会议
香港
英文
818-825
2012-07-27（万方平台首次上网日期，不代表论文的发表时间）