Effects are the major factors of zirconia ceramics sintering raw powder particle size, additives, sintering temperature and holding time, selection of salts and calcination conditions and atmosphere and the molding pressure, etc., they all have different degrees of influence on the performance of the material.
The sintering method of zirconia ceramics is the key to the ideal structure and predetermined performance of zirconia ceramics. The suitable sintering method can effectively reduce the sintering temperature. The sintering of Al2O3 ceramics is more than 1800, and the thermal pressure (20MPa) sintering is close to the theoretical density of the products at about 1500, while the static pressure sintering (400MPa) at high temperature has been densified in about 1000.
The greater the lattice energy in the crystal, the stronger the ion bond, the more difficult the diffusion of ions, the higher the sintering temperature. Different crystal combinations are different, so the sintering temperature is very different, even for the same crystal sintering temperature is not a fixed value.
In sintering high temperature stage, bulk diffusion is the main factor, while at low temperature, surface diffusion is the main factor. If the sintering of materials is long at low temperature, not only does not cause densification, but the surface diffusion changes the shape of stoma and causes damage to the performance of the system. Therefore, it is theoretically possible to rise from low temperature to high temperature as quickly as possible to create the conditions of volume diffusion.
The content of zirconia in zirconia ceramics is related to the temperature suitable for sintering. Generally the more the zirconia content is high, so the higher the sintering temperature is used, we can also design for him to choose the appropriate porcelain, appropriate flux can also help the zirconia ceramic sintering temperature down. Inside the corresponding design method, zirconia ceramics will join many additives, can promote the sintering of zirconia ceramic, so we can he divided into two categories, one is the solid liquid additives, and is a kind of additive in liquid phase.
