Microstructure and Mechanical Properties of PMS-PZT Ceramics with Silica Additives

摘要

The use of lead zirconate titanate ceramics for high power application must have superior mechanical properties, the composition Pb_(0.98)Sr_(0.02)(Mn_(1/3)Sb_(2/3)) _(0.05)Zr_(0.48)Ti_(0.47)O_3 + x wt percent SiO_2 (x = 0-1.0) have been studied for this purpose. The microstructures were observed to study the improvement of mechanical properties by SEM and TEM. The nano-scale secondary phase of SiO_2 and PbSiOs were observed on the grain boundary and the twinned ZrO_2 was found surrounded by PMS-PZT perovskite phase. The mechanism to the occurrence of twinned ZrO_2 and its content increased with increasing Si concentration are discussed in the paper. The occurrence of the nonferroelectric phase such as ZrO_2, SiO_2 and PbSiO_2 on the grain boundary should be the main reason for great improvement of fracture strength.