(Na_(0.5)K_(0.5-x)Li_x)NbO_3高温无铅压电陶瓷性能研究

为降低成本,采用传统电子陶瓷工艺制备了(Na0.5K0.5–xLix)NbO3(x=0.057～0.066)无铅压电陶瓷。Li取代K可以明显提高样品的居里温度(tC),x=0.066时样品的tC高达510℃,比纯(Na0.5K0.5)NbO3陶瓷高70℃左右。x=0.064时样品的d33高达212pC/N,kp为45.7%。x=0.063～0.066时样品的tanδ均低于0.020。特别是,x=0.066的样品经450℃退火24h,d33仍高达125pC/N。实验表明,(Na0.500K0.434Li0.066)NbO3是高性能的高温无铅压电陶瓷。

Study on the performance of (Na_(0.5)K_(0.5-x)Li_x)NbO_3 high-temperature lead-free piezoelectric ceramics

In order to reduce the cost, (Na0.5K0.5-xLix)NbO3 (x = 0.057 ~ 0.066) lead-free piezoelectric ceramics were fabricated by the traditional electroceramic processing. It is found that Curie temperature (tC) of the ceramic samples substituted by Li for K is obviously raised, tC of the sample of x = 0.066 is as high as 510 ℃ with 70 ℃ higher than the pure (Na0.5K0.5)NbO3 ceramic. The piezoelectric constant (d33) is as high as 212 pC/N, and planar electromechanical coupling factor (kp) reaches 45.7% for the sample of x = 0.064. The dielectric loss (tanδ) of the samples of x = 0.063 ~ 0.066 is below 0.020. Especially, the sample of x = 0.066 still has a high d33 value of 125 pC/N after 24 h annealing at 450 ℃. These results indicate that(Na0.500K0.434Li0.066)NbO3 is a high-temperature lead-free piezoelectric ceramics with high performance.