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The project by the National Natural Science Foundation of China (Project No.: 50735002) and Jiangsu Province high-tech research project (project number: BG2006005) funded. Piezoelectric ceramic material as a mechanical energy and electrical energy coupled to each other, widely used in household appliances, industrial products, aerospace and other fields in recent decades. Currently, the piezoelectric material used in the production and life mainly lead zirconate titanate based piezoelectric ceramic. However, this system materials will be generated in the preparation process of lead pollution, and related devices scrapped after process will bring the environmental harm unrecoverable. Research and development of environment-friendly lead-free piezoelectric materials become an urgent task. Potassium sodium niobate-based lead-free piezoelectric ceramics is one of the present study is more extensive lead-free piezoelectric material. Compared with the lead zirconate titanate-based piezoelectric ceramic, potassium sodium niobate-based lead-free piezoelectric ceramic having a high Curie point, but there are also a low dielectric constant and piezoelectric properties, insufficient sintering difficulties. To solve these problems, this paper for the study of potassium sodium niobate-based lead-free piezoelectric ceramics, from the composition design, the sintering process, doping modification of the microstructure and electrical properties of the material system. Ordinary prepared by solid 0.96 0.5 ) NbO (K 0.5 Na 3 -0.04LiTaO 3 piezoelectric ceramics , different doping amount of MgO its sintering temperature. The results show that: the incorporation of MgO so that the material in the lower temperature to complete the densification process, and obtain the comprehensive performance of the piezoelectric ceramic material. When the content of MgO is 0.25 mass%, the sintering temperature of the material can be reduced to 1060 ° C, and a performance of D 33 = 128 pC / N, and K p = 33.4% , Q m = 149, ε r = 611, tanδ = 2.84%. To further optimize the [(K 0.48 Na 0.535 ) 0.94 Li 0.06 ] NbO 3 piezoelectric properties, its doped Yb 2 O 3 modified. Studies: rare earth metals Yb 3 incorporation can significantly improve the sintered density of the material, to improve the performance of the material. The doping amount is excessive material grain refinement, performance declines. The yb 2 O 3 content of 1 mass%, better overall performance of piezoelectric ceramic: ρ = 4.5484 g / cm 3 , d 33 = 156 pC / N, k p = 37.69%, ε r = 1051, tanδ = 3.8%. Goal to improve the material Curie temperature and OT transition temperature, the research alkali metal group elements Li Rb and Cs introduction (K < sub> 0.5 Na 0.5 ) Nb 0.8 Ta 0.2 O 3 ceramic material use temperature range investigated. The results show that the addition of 0.04 mol Li 2 CO 3 can enhance the stability of the materials of tetragonal, to raise the Curie temperature of the material, the OT transition temperature is also reduced to around room temperature, improve the performance of the ceramic material at room temperature: d 33 = 185 pC / N, the K p = 44%, the T- C = 335 ° C, T OT = 32 ° C, tanδ = 4.2%.
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