Preparation of lead metaniobate high temperature ceramic with tungsten bronze structure relates to high temperature piezoelectric ceramics, PbNb₂O₆ piezoelectric ceramics have many outstanding features, such as poor quality factor (Qm <10), the single vibrational mode (Kt >> Kr) and high Curie temperature (Tc = 570 ℃), etc.. So it has a very broad application in the prospects of industrial inspection, medical diagnostics and high-temperature sensors.

 

There is the preparation process of metaniobate lead high temperature ceramics with tungsten bronze structure, the formula of the ceramic composition is Pb_1-xMe_xNb₂O₆(Base material)+additive ywt％(the total weight of base material is 100), of which, Me=Ca、Ba; x=0.02～0.12; the additives are Sm₂O₃、Ce₂O₃、Nd₂O₃ and Te₂, y=0.03～0.3％. The specific preparation process is as follows. 

 

Powder synthesis: Mix PbNb2O6 as the stoichiometric formula and the nanoscale (~ 100nm) CaO, BaO, TiO₂ and Sm₂O₃, Ce₂O₃, Nd₂O₃ and Te₂, put into the ball mill, the ratio of ball and materials is 1:5, mix for 6 to 8 hours, the powder was taken out briquetting (pressure 100MPa), in a sintering furnace at a heating rate of 2 ~ 5 ℃ / min, heated to 850 ℃, and after heat preservation for 2 hours to cool at the rate of > 250 ℃ / min to room temperature, and then take out and pulverized compacts and placed them into the ball mill finely grounding for 6 to 8 hours, the powder is moved to the sintering furnace, the temperature rose at heating rate of 2 ~ 5 ℃ / min to 1260 ~ 1270 ℃, and after heat preservation for 2 hours to cool at the rate of > 250 ℃ / min to room temperature, and transferred to the ball mill for fine grinding 32 to 48 hours, the powder for ceramic synthesis is obtained.

 

(2) Ceramic firing and polarization: Make the resulting powder into the piezoelectric ceramic green bodies by adding adhesive dry pressing method, after green bodies plasticized, put into an alumina crucible, in a sintering furnace with a heating rate of 2 ~ 5 ℃ / minute, sintered at 1290 ~ 1315 ℃, after heat preservation for 0 to 0.5 hours, to cool at 250 ℃ / min cooling rate, after cold working and the trimming, and then placed in the eight shelves at 5000V / mm / 180 ℃ / 10min, go through high power polarization, to obtain the piezoelectric ceramic products.