Synthesis and Its Microstructure of Calcium Dialuminate Materials with Low Thermal Expansion Coefficient
LI Youqi,KE Changming,LI Nan(Hubei Province Key Laboratory of Ceramics and Refractories, Wuhan University of Science and Technology, Wuhan 430081)
Calcium dialuminate (CA_2), a low thermal expansion coefficient material, is synthesized by reaction sintering of two kinds mixtures of CaCO_3/α-Al_2O_3 and pure calcium aluminate cement/α-Al_2O_3 respectively. The effects of raw materials,reaction temperatures and compact pressure on the sintering properties of the product are studied. Meanwhile, the low thermal coexpansion efficient of CA_2 is measured. Their reaction evolution and phase change are determined and observed by means of XRD, TG-DSC and SEM. The results show that (1) CA_2 can be synthesized by reaction sintering of two kinds of the mixtures of CaCO_3/α-Al_2O_3 and pure calcium aluminate cement/α-Al_2O_3.(2)The compact pressure hardly gives any obvious effects on the sintering properties in these two experiments.(3)The sintering properties and microstructure of specimens differ from the raw materials and reaction temperature.
【CateGory Index】： TB39