Microwave heating sintering uses the interaction between microwaves and ceramics. Because of the dielectric effect, the inner and surface of the ceramic are sintered at the same time. Microwave sintering is different from other sintering methods. Its hot gas flow is from the inside to the outside, which is conducive to the outward diffusion of the gas inside the green body; at the same time, the microwave increases the activity of the crystal grains, and is easier to migrate to promote densification.
Compared with other sintering methods, microwave sintering can quickly heat up and sinter. The temperature field is uniform, the thermal stress is small, and there is no pollution. The sintering temperature of microwave sintering is 100 to 150% lower than that of conventional sintering. The sintering time is nearly an order of magnitude shorter than that of conventional sintering. Sintered under the same conditions, the density of microwave sintering is obviously higher than that of conventional sintering. Microwave sintering can sinter objects with complex shapes, and the sintered ceramic has small internal grains, good uniformity, and good fracture toughness.