Fabrication and Properties of CaAl_(12)O_(19)-Al_2O_3 Composite Ceramics

摘要

CaAl_(12)O_(19)-Al_2O_3 composite ceramics were synthesized by in situ solid-state reaction using CaCO_3 and industrial C1-Al_2O_3 powders. The effects of sintering temperature and CA_6 (CaAl_(12)O_(19)) content on phases and microstructure of the final composites were studied by XRD and SEM. The results showed that sheet-like CA_6 appeared in the materials when sintering temperature was higher than 1400°C and grew up with increasing sintering temperature. The optimum sintering temperature was 1600°C. The sample with 20wt% CA_6 had the bulk density of 3.21g·cm~(-3), the apparent porosity of 9.94% and the bending strength of 149.88MPa. With the increasing of CA_6 content in the final composite ceramics, the bulk density and the bending strength increased firstly and then decreased. The lowest apparent porosity 1.42%, a density of 3.60g/cm~3 and the highest bending strength of 265.10MPa were achieved for the sample containing 10wt% CA_6 sintered at 1600°C.