Preparation of γ-LiAlO2 green bodies through the gel-casting process

An aqueous gel-casting process using methacrylamide (MAM) as monomer and N,N′-methylenebisacrylamide (MBAM) as crosslinker was developed for γ-LiAlO2 ceramics. The precursor γ-LiAlO2 powder with mean particle size of 3.4 μm was synthesized via solid-state reaction process. The zeta potential of the γ-LiAlO2 powders in deionized water and viscosity of the slurries with different solid loadings were measured. It was found that the solid loading of the γ-LiAlO2 slurry that met the requirement of gel-casting could reach 56 vol.%. The effects of pH values and the kind of initiator on the copolymerization of MAM/MBAM were investigated. The green bodies with the binder content of 5.3 wt% exhibited a compressive strength of 12.6 MPa and a yield point as high as 6.4 MPa. SEM results revealed homogeneous and compact morphology of the green bodies. In addition, the compressive strength of the sintered γ-LiAlO2 bodies were studied simultaneously.