中文摘要：

人类社会可持续发展的要求以及一些发达国家有关电子产品无铅化法规的全面实施，近年来无铅压电陶瓷的研究与开发受到极大关注。碱金属铌酸盐系压电陶瓷以其优越的压电性能和较高居里温度受到人们高度重视。结合近年有关KNbO3-NaNbO3（KNN）基无铅压电陶瓷的报道，着重从KNN基压电陶瓷的相变特性、掺杂改性和引入第三组元等几个方面，介绍了相关研究的现状，并对KNN基压电陶瓷的发展趋势进行了展望。

英文摘要：

With the need of sustainable development and the legislation on lead-free being enforced in some developed countries, especially for the non-lead contained in electronic components, alkali niobate lead-free piezoelectric ceramics have been attracted more attention with their superior properties and higher Curie temperature. According to the reports of KNbO3-NaNbO3 （KNN） -based lead-free piezoelectric ceramics in recent years, the current progresses of KNN based ceramics is summarized and reviewed with emphasizes on the characteristics of their phase transition, the modification of their properties, and the introduce of the third component of their compositions in this paper. The future prospect of KNN based piezoelectric ceramics is also predicted