铌酸钾钠压电陶瓷的性能研究
毕业论文 关键词 无铅压电陶瓷 (K0.5Na0.5)NbO3基 固相烧结法 烧结温度
Title Study on properties of potassium sodium niobate piezoelectric ceramics
Abstract Piezoelectric and ferroelectric ceramic materials have been widely used in the fields of transducers, actuators, filters, resonators and other frequency components, and is a kind of important functional materials. From the environmental protection and sustainable development perspective, lead-free piezoelectric ceramics is the development direction of piezoelectric ceramic materials. This topic from the KNN based lead-free piezoelectric ceramics of using solid-phase sintering, with K2CO3 and Na2CO3 and Nb2O5 as the main raw material, the raw materials by ball milling, drying, calcining, crushing, forming, plastic drainage, sintering and annealing etc. process, under the different temperature sintered ceramic samples. The influence of sintering temperature on the structure and properties of the sintered products was studied. The optimum sintering temperature range of the product performance and structure was discovered. According to the experimental results, the following conclusions are drawn: (1) KNN ceramics prepared by solid state sintering method, the morphology and structure of the 1085℃-1095℃. When the sintering temperature is relatively low, the ceramic grains are not completely crystallized; while the sintering temperature is relatively high, some of the ceramic grain is melted, which leads to the grain refinement. (2) The piezoelectric properties of sintered KNN lead-free piezoelectric ceramics sintered at 1085 ℃ -1985 ℃ are also very good, although the samples sintered at 1080 ℃ and 1100 ℃ are lower, but they are better than the samples prepared by molten salt method. It shows that there is still much room for improvement in the traditional solid state sintering process. (3) The dielectric properties of sintered samples at 1085℃ -1095℃. At the lower temperature of 1080 ℃, and the higher temperature of 1100 ℃, due to the refinement of the ceramic internal grain, and other reasons, so that the polarization of the ceramic chip, which leads to the decrease of the dielectric properties of the sample. The same reason can also affect the performance of KNN lead-free piezoelectric ceramics ferroelectric hysteresis loop.