K0.5Na0.5NbO3 precursor powders with pure phase and mean grain size of 100 nm were obtained via normal milling and high-energy ball milling methods. As one liquid phase, deionized water was added into the precursor powders. K0.5Na0.5NbO3 ceramics with the simple composition were prepared by means of cold sintering and post-annealing. Effects of cold-sintering temperature, cold-sintering time, pressure on phase and densification of the cold-sintered pellets were studied. The cold-sintered pellets were post-annealed at various temperatures. Effect of annealing temperature on dielectric and ferroelectric properties of the post-annealed ceramics was studied. The ceramics prepared at cold-sintering temperature 180 ℃ and annealing temperature 1 100 ℃ show dielectric constant 345, dielectric loss 0.03 at room temperature, remanent polarization 25.8 μC/cm2, maximum polarization 31.4 μC/cm2, and coercive field 10.2 kV/cm. The dielectric and ferroelectric properties are better than those of the ceramics prepared via the normal solid-state sintering method.

K0.5Na0.5NbO3 ceramics; cold sintering;dielectric property;ferroelectric property