The Effect of Nano CuO as Sintering Aid on Phase Formation, Microstructure and Properties of Li2O-Stabilized beta ''-Alumina Ceramics

摘要

Li2O-stabilized beta ''-alumina powder was synthesized in the double zeta process with Al2O3, Na2CO3 and Li2CO3 as the starting materials. The effect of nano CuO additive as the sintering aid on phase formation, microstructure, mechanical and electrical properties of Li2O-stabilized beta ''-alumina ceramics was investigated by means of x-ray diffraction (XRD), scanning electron microscope (SEM), biaxial flexure test (BFT) and ionic conductivity test. The results indicated that the fracture strength of the samples improved with the addition of a low concentration of nano CuO, which can be attributed to the higher density and more uniform microstructure. The optimal amount of nano CuO was determined at about 1.5 mol%, with the addition of which the ionic conductivity was approximately twice as high as that of the sintered samples without any nano CuO.