The Characteristics Of Zirconia Ceramics
Pure ZrO2 is white, contain impurity when yellow or gray, generally contain HfO2, not easy to separate. The world's proven zirconium resources are about 19 million tonnes, and zirconia is usually purified from zirconium ores. Under atmospheric pressure, there are three kinds of crystal states: Single oblique (monoclinic) zirconia (M-zro2), ZrO2 (tetragonal) zirconia (T-zro2) and Cubic (Cubic) zirconia (C-zro2), the above three crystalline types exist in different temperature ranges, and can be transformed into each other:
Single Oblique (monoclinic) zirconia (M-zro2) <950℃5.65g/cc
Sifang (tetragonal) zirconia (T-zro2) 1200-2370℃6.10g/cc
Cubic (Cubic) zirconia (C-zro2) >2370℃6.27g/cc
The above three kinds of crystalline states have different physicochemical properties, and in practical application, in order to obtain the required crystal shape and performance, the different types of stabilizers are usually added into different types of zirconia ceramics, such as partially stabilized zirconia (partially stabilized zirconia, PSZ), When stabilizer for Cao, MgO, $literal, respectively expressed as Ca-psz, Mg-psz, Y-psz and so on. The square zirconia composed of metastable T-zro2 is called the square zirconia polycrystalline ceramics (tetragonal zirconia polycrysta, TZP). When the stabilizer is $literal and CeO2, it is respectively expressed as TZP, CE-TZP, etc.