Zou Wenjun

Effects of CeO2 Addition on Microstructure and Mechanical Properties of PNW-PMN-PZT Piezoelectric Ceramics

Abstract Microstructure and mechanical properties of CeO 2 doped Pb 0.94 Sr 0.06 (Ni 1/2 W 1/2 ) 0.02 (Mn 1/3 Nb 2/3 ) 0.07 (Zr 0.51 Ti 0.49 ) 0.91 O 3 (PNW-PMN-PZT) were investigated. The results indicated that the solution limit of CeO 2 was about 5% (mass fraction), and a phase transition from tetragonal to rhombohedral would occur with the increase of the CeO 2 dopant. Meanwhile, the tetragonallity also increased with the increase of the CeO 2 dopant. Incorporation of CeO 2 could suppress the grain growth and increase the remnant strain on the grain surface. Compositional non-homogeneity and serious Fe element segregation at grain boundaries was found due to the doping of CeO 2 . Owing to brittleness of the glassy phase, the fracture behavior of the materials tended to occur at the Fe-rich grain boundaries. The ceramic with 5% CeO 2 addition showed good mechanical properties with the hardness 115 and the flexural strength 112.9 MPa, which should be attributed to the effects of a suitable CeO 2 addition on the grain growing, remnant strain and densification.