Zirconia Ceramics Doped And Electrical Conductivity Research

The bending energy of Zr-O is very high, so the ZrO2 shows a series of excellent performance like high melting point, high hardness and strength, good chemical stabilization and so on. The ZrO2 has very wide range applications, commonly used for high-performance structural ceramic. However, the ZrO2 have three kinds crystal phase, cube, tetragonal and monoclinic, and the energy gap of the three crystal phases are all over 4 ev, and the ZrO2 is a kind of insulating material under normal temperature conditions. So the ZrO2 has not been applied in the field of conductive material of normal temperature yet.In this experiment, the ZrO2 ceramics has a wide range conductive ability were prepared by doping for ZrO2, using the traditional dry pressing molding and atmospheric sintering method. The effects for electrical conductivity of ZrO2 ceramic were invested, including different type dopant, dopant concentration and sintering temperature respectively. The main contents and conclusions were as follows:1. The carrier conductive dopant MgO, ZnO, Nb2O5, WO3 can't improve the conductivity of ZrO2 ceramic effectively. The bending energy of Zr-O is very high, so the carrier bond strongly to it, in addition the migratory activation energy for the carrier under room temperature is pretty high, so the carrier conductive dopant can't improve the conductivity effectively, but basically make ZrO2 ceramics achieve the requirements of electrostatic dissipative and can be applied to anti-static materials field.2. The network conductive dopant TiN can improve the conductivity of ZrO2 ceramic effectively, and there is no upper limit for the dopant concentration. It's easily to get desired conductivity by adjusting the dopant concentration. TiN was dispersed in the ZrO2 ceramic, due to it's good conductivity when the TiN concentration arrived the conductive threshold the TiN particle will form a conductive network, so the electricity can transfer. When the concentration of TiN between 5-20 wt%, the ZrO2 ceramic can be used as anti-static material. While the TiN content over 25 wt%, the ZrO2 ceramic turn to be a conductive material, the minimum value this experiment got was 10-4 ??cm.3. The melting point of TiN is very high, while doped with relative high concentration TiN, the density, bending strength and the hardness increase with the sintering temperature, also, the electrical conductivity significantly improved. However, when doped with relative low concentration TiN, it is prone to occur over-sintering as the temperature increase, the density decrease slightly but the mechanical performance didn't show an obvious decline.