What is tetragonal zirconia ceramic polycrystalline?How to keep TZP

The tetragonal zirconia ceramic polycrystal has high strength and fracture toughness, but a certain stabilizer must be added in the preparation process to maintain the high performance of TZP. Below, Pintejin Ceramics Factory will introduce the tetragonal zirconia polycrystal and the How to keep its high performance.

The grains of this ceramic material are very small. In order to keep the metastable tetragonal phase, ultra-fine and high-purity zirconia powder must be used, and the Y2O3 content must be accurately controlled. °C).

alumina ceramic tube Tetragonal zirconia ceramics (TZP) have high strength and fracture toughness through transformation toughening, but at medium and high temperature due to the gradual disappearance of transformation toughening effect, the mechanical properties decline rapidly. Adding the second phase particles into the TZP matrix to form a composite material is an effective method to improve the toughness and high temperature mechanical properties of TZP.

Y-TZP is polycrystalline tetragonal ZrO2 containing yttrium. It has excellent mechanical properties such as high strength, high fracture toughness, and high wear resistance, but at 200~300℃, the phenomenon of strength “degradation” occurs, which is mainly due to the transformation of tetragonal to monoclinic, resulting in a large number of tiny cracks. To. As mentioned above, tetragonal-monoclinic can cause phase transition with temperature change, and it is also closely related to the particle size of tetragonal phase. As the particle becomes smaller, the phase transition strength also decreases. When the particle size is below a certain level, the phase transition will not occur even if the temperature is lowered to room temperature or lower, so in order to prevent its phase transition from occurring, only reducing the particle size can maintain the high performance of TZP.

Yellow zirconia ceramic rod YT double grain size must be less than 1m, generally controlled within 6~9pm for Ce-TZP. As the process is different, its strength is also different. Y-TZP adopts three processes of normal pressure, hot pressing and isostatic pressing, and the flexural strength at room temperature is 1000~1300MPa, 1500~1700MPa and 2500MPa respectively.