中文摘要：

用传统固相烧结工艺制备致密Na0.5Bi4.5Ti4-xO15（x=0,0.02,0.04,0.06,0.08）系列铋层结构压电陶瓷,研究该系列陶瓷的微观结构、介电性质和压电性质。结果表明：少量Ti不足可以促进Na0.5Bi4.5Ti4O15陶瓷晶粒长大并使陶瓷的压电性能获得较大提高;随着x增大,陶瓷的压电常数和机电耦合系数都在x=0.06时呈现最大值,分别为20pC/N和28%。该系列陶瓷压电性能获得较大提高的主要原因可能与Ti不足（或Na、Bi过量）引起的晶格畸变有关。

英文摘要：

Bismuth layer-structured Na0.5Bi4.5Ti4–xO15（x = 0,0.02,0.04,0.06,0.08） ceramics were fabricated by conventional solid state process.Microstructure,dielectric and piezoelectric properties of these ceramics were investigated.It is found that a small amount of Ti deficiency can promote grain growth and improve the piezoelectric properties of Na0.5Bi4.5Ti4O15 ceramic.The best piezoelectric properties were obtained for the composition with x = 0.06,d33～20 pC/N and kt～28%.The lattice distortion caused by Ti deficiency may explain the enhancement of piezoelectricity in Na0.5Bi4.5Ti4–xO15 ceramics.