The initial raw material of zirconia products is zirconium silicate, which is changed into zirconium oxychloride and other compounds after chemical desilication treatment.
We get the precursor from rare earth oxides and zirconium oxychloride after alkaline neutralization and co-precipitation reaction, and then after calcination, air flow and spray granulation, it turns into zirconia products mainly raw materials –zirconia powder.
Zirconia powder was be made into raw billet by different means of molding – including dry pressure, isostatic pressure, extrusion, rolling, injection and so on. After high temperature it was sintered into porcelain, and then after polishing and finishing, it was made into various types of products.
In the 1960s Garvi et al. used calcium oxide, magnesium oxide partially stabilized zirconia (Ca-PSZ, Mg-PSZ) to achieve phase transition toughening; Since then scholars at home and abroad have fully investigated different zirconia stabilizers, and studied the effect of rare earth compound addition on the mechanical properties, material appearance, and aging resistance of zirconia ceramics from the ideas of microstress, lattice manifolds, and so on. The physical and chemical properties of rare earths are used to change the lattice phase transition of zirconia, avoiding the monoclinic phase transition of zirconia at low temperatures, thus effectively stabilizing the tetragonal phase of zirconia. It is found that Y2O3, CeO2 is one of the best stabilizers for ZrO2 to form a stable cubic phase. Using the properties of tetragonal and cubic phase zirconia (TZP) can be manufactureed into rare-earth zirconia structural products, which at the same time have the advantages of high wear and corrosion resistant and high mechanical strength. The material properties are shown in the table below, which is the best strength and toughness of the ceramics at present:
性能 | 单位 | 参数 |
成分 | Yttria Stabilized Zirconia | |
材料密度 | g/cm3 | 6.0-6.13 |
硬度 | HV | 1300 |
抗弯强度 | Mpa | 1200-2000 |
断裂韧性 | MPam½ | >12 |
弹性模量 | GPa | 205 |
导热系数 | W/m.k | 3 |
热膨胀系数 | 10×10-6/°C
(20—400°C) |
9.6 |