中文摘要：

铌酸钠钾（KNN）基无铅压电陶瓷性能的提高可通过掺杂、取代和添加烧结助剂等方法来实现，还可通过适当改变陶瓷制备工艺来达到。为了探索可实用化的KNN陶瓷制备工艺，以纯KNN陶瓷的制备为例，考察了3种不同粉体制备工艺（包括传统固相反应法、原料中添加活性炭的固相反应法、以及粉体经分批预烧处理后再混合的固相反应法）对KNN无铅压电陶瓷的晶相、微观结构和电学性能的影响。实验结果表明：采用原料中添加活性炭的固相反应法制得的纯KNN陶瓷，其表面晶粒尺寸相对均一，晶界清晰，样品致密性好；所得的陶瓷样具有较好的介电、压电性能，其中d33=116pC／N，kp=0．37，ε=630，tanδ=0．034，Pr=22．40μC／cm^2，Ec=0．675kV／mm，Tc=405℃。

英文摘要：

It is noticeable that enhanced properties of KNN based lead-free piezoelectric ceramics can be obtained not only via doping, substitution and sintering-aid adding, but also via modified ceramic-preparing techniques. In order to optimize the modified ceramic-preparing techniques which can be practically used in lead-free piezoelectric ceramics preparation, three kinds of powder-preparing techniques were tested in present studies, inclu- ding the conventional mixed-oxide method, the conventional mixed-oxide method with active carbon adding in raw material and the method for different patches of pre-synthesized powder then mixing, and the effects of the processing techniques on the crystallite phase, microstructure and electrical properties of KNN lead-free piezoelectric ceramics were analyzed. It is concluded that by using the technique of the conventional mixed-oxide meth- od with active carbon adding in raw material much better crystalline and compact KNN ceramics can be obtained, and the pure KNN ceramics show much better dielectric, piezoelectric and ferroelectric properties （d33=116pC/N,kp=0.37,ε=630,tanδ=0.034,Pr=22.40μC/cm^2,Ec=0.675kV/mm,Tc=405℃）