Improvement of microcracks resistance of porous aluminium titanate ceramic membrane support using attapulgite clay as additive

摘要

Attapulgite (ATP) clay as an important ceramic raw material appears with natural nano-rod like morphology and widely co-exists with other minor minerals. To improve the mechanical performance and to reduce the sintering temperature of aluminium titanate (AT) ceramic membrane support, porous aluminium titanate ceramic has been prepared from Al2O3-TiO2 system mixed with attapulgite clay by solid-phase reaction at relative low temperature 1300 degrees C. The added contents of attapulgite clay were 0%, 10%, 15%, 20%, 25% and 30% in weight percent ratio, respectively. The phase composition, open porosity, strength, sintering behavior and microstructure as well as pore size distribution of porous aluminium titanate ceramic were systematically investigated. The XRD analysis suggests that the enhanced secondary phase mullite was produced when sintering temperature was above 1200 degrees C with added attapulgite clays. The SEM images show that microcracks caused by the grain anisotropy of generated aluminium titanate were increased with the rising of sintering temperature. Both the maximum pore size and average pore size decrease with the increasing sintering temperature as the specimen was reacted with some attapulgite clay. Under the condition of 25 wt% attapulgite clay addition and sintering temperature of 1300 degrees C, the obtained porous ceramic membrane support of aluminium titanate has a open porosity of 32.41% and bending strength of 45.48 MPa.